Displaying 1 - 322 of 322 tests
AATAlpha-1-Antitrypsin (AAT) is useful in the study of inherited AAT deficiency, benign and malignant hepatic tumors and yolk sac carcinoma. Sensitivity and specificity of the results have made this antibody a useful tool in the screening of patients with cryptogenic cirrhosis or other forms of liver disease with portal fibrosis of uncertain etiology. Immunohistochemistry (IHC)
Acid Phosphatase (AcP)

Cytochemical stain.

Immunohistochemistry (IHC)
ACTHAnti-adrenocorticotropic hormone (ACTH) is a useful marker in the classification of pituitary tumors and the study of pituitary disease. It reacts with ACTH-producing cells (corticotrophs). It also may react with other tumors (e.g., some small cell carcinomas of the lung) causing paraneoplastic syndromes by secreting ACTH. Immunohistochemistry (IHC)
AdenovirusAdenoviruses are simple DNA-containing viruses that multiply in the cell nucleus. They induce latent infections in tonsils, adenoids and other lymphoid tissue of man, causing either unapparent or limited illnesses that are followed by complete recovery and persistent type-specific immunity. This antibody is directed against adenovirus, allowing for the rapid identification of viral infections in tissues. Immunohistochemistry (IHC)
AFBSpecial stain. Ziehl-Neelsen Acid-Fast Bacilli Stain is used to detect the presence of acid-fast mycobacteria in tissue sections. Acid-fast techniques are of value in the detection of mycobacteria, rod-shaped organisms that sometimes exhibit filamentous (fungus-like) growth. The most significant disease-producing mycobacteria are Mycobacterium tuberculosis and Mycobacterium leprae. Immunohistochemistry (IHC)
AFPAlpha-1-fetoprotein (AFP) is a 64 kD tumor-associated embryonal antigen produced by fetal liver, hepatocellular carcinoma, yolk sac tumor and several germ cell tumors of testicular and ovarian origin. Most non-seminomatous germ cell tumors produce AFP. AFP is of importance in diagnosing hepatocellular carcinoma. Immunohistochemistry (IHC)
Alcian BlueSpecial stain. Alcian blue is intended to identify weakly sulfated mucins in tissue samples. Immunohistochemistry (IHC)
ALK (D5F3)

VENTANA FDA approved ALK (D5F3) CDx Assay is intended for the qualitative detection of the anaplastic lymphoma kinase (ALK) protein in formalin-fixed, paraffin-embedded (FFPE) non-small cell lung carcinoma (NSCLC) tissue stained with a BenchMark XT or BenchMark ULTRA automated staining instrument. It is indicated as an aid in identifying patients eligible for treatment with XALKORI® (crizotinib) or ZYKADIA® (ceritinib).

Immunohistochemistry (IHC)
ALK-1 (for heme cases)The ALK1 (ALK1 cline) antibody labels normal human ALK protein and the NPM-ALK chimeric protein, and is a useful tool for the identification of the subgroup of anaplastic large-cell lymphomas (ALCL) that are ALK positive. Immunohistochemistry (IHC)
Amyloid A & Amyloid PAmyloid A and P react with amyloid deposits in many tissues. When accompanied by Congo Red, Amyloid A and P can be used to distinguish primary and secondary amyloidosis. Because these stains are interpreted in context of each other and Congo Red, testing options available to global and tech-only clients differ. Immunohistochemistry (IHC)
Annexin A1Annexin A1 (ANXA1), a gene related to phagocytosis, is found to be one of the most highly upregulated genes in hairy cell leukemia. Annexin A1 is strongly expressed on the cell membrane of 97% of hairy cell leukemia cases. Although Annexin A1 is negative in normal B-cells or B-cell tumors other than "classic" hairy cell leukemia, it stains myeloid cells, macrophages, and subsets of benign T-cells. Immunohistochemistry (IHC)
ARAndrogen receptor (AR) is responsible for the regulation of the growth of the prostate epithelial cells. In untreated prostate carcinoma, AR positive cells are more likely to be responsive to hormonal therapy. In patients with hormone refractory prostate carcinoma, the presence of AR has a negative prognostic impact. It is also commonly expressed in salivary duct carcinoma. Immunohistochemistry (IHC)
Arginase 1Arginase 1 (ARG1), also known as liver arginase, is a binuclear manganese metalloenzyme. ARG1 is abundantly expressed in liver and represents a sensitive and specific marker of benign and malignant hepatocytes that may be a useful diagnostic tool in routine surgical pathology practice. Immunohistochemistry (IHC)

ATRX mutations predominantly occur in grade II/III astrocytoma and secondary glioblastoma multiforme (GBM) brain tumors. ATRX loss defines a subgroup of astrocytic tumors with a favorable prognosis.

Immunohistochemistry (IHC)
B72.3This monoclonal antibody (B72.3) to tumor-associated glycoprotein recognizes a tumor-associated oncofetal antigen (TAG-72) expressed by a wide variety of human adenocarcinomas. This antigen is expressed by most invasive ductal breast, colonic, pancreatic, gastric, esophageal, lung, ovarian and endometrial adenocarcinomas. This antigen is also expressed on normal secretory endometrium, but not on other normal tissues. Immunohistochemistry (IHC)

BAP1 IHC stain is a tool for detection of BAP1 mutations with subsequent inactivation. Loss of BAP1 by IHC is 100% specific for malignant mesothelioma in the context of mesothelioma vs. mesothelial hyperplasia. Loss of BAP1 may be seen in other neoplasms.

Immunohistochemistry (IHC)
BCA-225This antibody recognizes a human breast carcinoma associated glycoprotein BCA-225 (220-225kD). This protein differs in size and distribution from other breast carcinoma antigens. It does not react with benign or malignant gastrointestinal tissues. It can be used to identify skin carcinomas with sweat gland and sebaceous differentiation. Immunohistochemistry (IHC)
BCL1/Cyclin D1BCL1/Cyclin D1 is a nuclear protein detectable in formalin-fixed, paraffin-embedded (FFPE) sections and is found in the majority of mantle cell lymphomas. Hairy cell leukemia and plasmacytoma may also express BCL1 with a weaker signal. BCL1 is an oncogene acting as a cell cycle regulator.  Immunohistochemistry (IHC)

BCL-10 is an N-terminal CARD (Caspase Recruitment Domain) containing protein that is involved in the adaptive immune response. It is also a substrate for MALT1. Mutations in the gene can lead to lymphoma, mucosa-associated lymphoid type. It is useful in the assessment of pancreatic tumors to distinguish acinar cell carcinoma from primitive neuroectodermal tumor (PNET), solid pseudopapillary tumor (SPT) and pancreatic blastoma (PB).

Immunohistochemistry (IHC)
BCL2B-cell lymphoma 2 (BCL2) was the first of the translocation-associated proteins to be identified in lymphoma. Most cases of follicular lymphoma have a [t(14;18)] translocation, resulting in BCL2 overexpression. Overexpression of BCL2 in activated diffuse B-cell lymphoma may predict disease progression. BCL2 is also expressed in a wide range of other neoplasms. See also BCL2 (SP66) IHC Immunohistochemistry (IHC)
BCL2 (SP66)

BCL2 is a protein associated with apoptosis regulation produced by the BCL2 gene and is comprised of an alpha and beta chain. BCL2 (clone SP66) shows negative reaction on reactive germinal centers and positive staining of neoplastic follicles in follicular lymphoma. This is useful in distinguishing between reactive and neoplastic follicular proliferation in lymphoid lesions. This is a sensitive antibody that may stain a greater proportion of follicular lymphomas than other BCL2 antibodies. See also BCL2 IHC. 

Immunohistochemistry (IHC)
BCL6BCL6 antibody stains the germinal center cells in lymphoid follicles, the follicular cells and interfollicular cells in follicular lymphoma, a subset of diffuse large B-cell lymphomas, and Burkitt lymphoma, as well as the majority of Reed-Sternberg cells in nodular lymphocyte predominant Hodgkin lymphoma. In contrast, BCL6 rarely stains mantle cell lymphoma and mucosa-associated lymphoid tissue (MALT) lymphoma. BCL6 expression is seen in approximately half of CD30+ anaplastic large cell lymphomas but is absent in other peripheral T-cell lymphomas. Immunohistochemistry (IHC)
BerEP4Ber-EP4 recognizes two glycoproteins of 34 and 49 kDa present on the surface and the cytoplasm of all epithelial cells except the superficial layers of squamous epithelial, hepatocytes and parietal cells. It does not label mesothelial cells and rarely marks mesotheliomas. It shows a broad spectrum of reactivity with human epithelial cells including simple epithelia and basal layers of stratified non-keratinized squamous epithelium and epidermis. Ber-EP4 reportedly distinguishes adenocarcinomas from pleural mesotheliomas. Immunohistochemistry (IHC)
Beta CateninBeta-catenin is an important regulator of cell–cell adhesion and embryogenesis. Mutations of beta-catenin could lead to some human cancers. Normal cells show membrane staining for beta-catenin, while cytoplasmic and/or nuclear staining is abnormal. Dysregulation of beta-catenin occurs in Gardner syndrome, where it leads to both familial adenomatous polyposis and fibromatosis. Nuclear location of beta-catenin also occurs in colon and endometrioid ovarian carcinomas as well as in synovial sarcoma, osteosarcoma, liposarcoma, palisaded myofibroblastoma, and other sarcomas. Immunohistochemistry (IHC)
BG8This antibody is specific for the Lewis Y (Type 2 Chain) carbohydrate antigen. Lewis Y has been evaluated as a clinical marker for the diagnosis and prognosis of cholangiocarcinoma, hepatocellular carcinoma and breast cancer. It was also shown that BG8 reacts predominantly with lung adenocarcinomas and is negative focally or weakly positive in epithelial mesotheliomas. Immunohistochemistry (IHC)
BOB1BOB1 is present in all B-cells expressing Ig. The combination of BOB1 and OCT2 staining is helpful in distinguishing between classical Hodgkin lymphoma (at least one marker negative) and nodular lymphocyte predominant Hodgkin lymphoma or T-cell histiocyte-rich large B-cell lymphoma (both markers expressed). Immunohistochemistry (IHC)
BRAF V600EA monoclonal antibody (VE1) against mutant BRAF (V600E) permits fast assessment of the mutant protein expression throughout a tumor sample in hairy cell leukemia, some melanomas, and some thyroid carcinomas. BRAF mutation is a strong molecular marker of poor prognosis in colorectal carcinoma (CRC), and can be used as evidence of a sporadic mechanism of mismatch repair deficiency. Immunohistochemistry (IHC)
BRCA1BRCA1 (breast and ovarian cancer susceptibility protein 1) is a nuclear phosphoprotein that plays a role in maintaining genomic stability and acts as a tumor suppressor. This test detects expression of BRCA1 protein and is not intended to identify germline or somatic (tumor) mutations in BRCA1. Available molecular tests may be viewed here Immunohistochemistry (IHC)
Breast Triple Stain (CK5 + p63 + CK 8/18)The combination of CK5 + P63 + CK8/18 (Breast Triple Stain) can be useful in distinguishing ductal carcinoma in situ (DCIS) from microinvasive breast carcinoma. This multiplex can decipher between a radial scar and infiltrating carcinoma. P63 (nuclear brown) and CK5/6 (cytoplasmic brown) stain myoepithelial cells, whereas CK8/18 labels the cytoplasm (red) of all ductal or lobular epithelium. Immunohistochemistry (IHC)
CA125CA125 reacts with most epithelial ovarian neoplasms of serous, endometrioid, clear cell and undifferentiated types. CA125 is a useful tumor marker for ovarian carcinomas; however, CA125 has also been described in other neoplasms such as seminal vesicle and anaplastic lymphomas. No reactivity has been shown for mucinous ovarian tumors. It reacts with both normal tissues and neoplasms of fallopian tube, endometrium, endocervix and mesothelioma. It does not react with colon cancer. Normal tissues such as breast, liver, skin, kidney and spleen are negative. Immunohistochemistry (IHC)
CA19.9In normal tissues, the CA19.9 antigen has been demonstrated in ductal epithelium of the breast, kidney, salivary gland, sweat glands, respiratory epithelium of the lung, colon epithelium, pancreatic acini and ducts, biliary epithelium in the liver and prostate epithelium. Gastrointestinal carcinomas are positive, as well as transitional cell carcinomas of the bladder, endometrial adenocarcinomas, thyroid papillary, gallbladder carcinomas and lung carcinomas, including adenocarcinomas, bronchoalveolar cell carcinomas, squamous and small cell carcinomas. Immunohistochemistry (IHC)
CalcitoninCalcitonin is secreted by thyroidal parafollicular cells of neuroectodermal origin, probably in response to hypercalcemia. The IHC demonstration of calcitonin is important: (1) For identification of early or microscopic medullary thyroid cancer (MTC), (2) To identify an MTC in the absence of amyloid deposits, (3) To distinguish non-typical forms of MTC (e.g., predominantly spindle cell or small cell patterns) from anaplastic carcinoma or malignant lymphoma, (4) To differentiate MTC with microfollicular or papillary patterns from thyroid follicular and papillary neoplasms and (5) To identify C-cell hyperplasia in association with hypercalcemia of diverse etiologies. Immunohistochemistry (IHC)
Calcium Stain

Special stain.

Immunohistochemistry (IHC)
CaldesmonCaldesmon is a developmentally regulated protein involved in smooth muscle and non-muscle contraction. Two closely related variants of human caldesmon have been identified. The h-caldesmon variant (120-150kDa) is predominantly expressed in smooth muscle and a subset of myoepithelial cells, whereas l-caldesmon (70-80kDa) is found in non-muscle tissue and cells. Neither of the two variants has been detected in skeletal muscle. Immunohistochemistry (IHC)
CalponinCalponin, a calmodulin, is involved in the regulation of smooth muscle contraction. The expression of calponin is restricted to smooth muscle cells. Two isoforms of calponin exist with molecular weights of 34kDa and 29kDa. Expression of the 29kDa form is primarily restricted to muscle of the urogenital tract. Calponin also labels myoepithelial cells and can be useful in distinguishing in situ from infiltrating breast carcinoma. Immunohistochemistry (IHC)

Calretinin is the most specific and reproducible positive marker of epithelial mesothelioma. Calretinin is a calcium-binding protein similar to S100 protein. It is found in the central and peripheral nervous system and in a wide spectrum of non-neural cells, including steroid-producing cells of ovaries and testes, fat cells, renal tubular epithelial cells, eccrine glands, thymic epithelial cells and mesothelial cells. Calretinin immunostaining is found in most epithelial mesotheliomas.

Immunohistochemistry (IHC)
CAM 5.2Anti-Cytokeratin (CAM 5.2) has a primary reactivity with human keratin proteins that correspond to Moll`s peptides #7 and #8, Mr 48 and 52 Kd. Cytokeratin 8 is present on secretory epithelia of normal human tissue but not on stratified squamous epithelium. CAM 5.2 stains most epithelial derived tissue, including liver, renal tubular epithelium, hepatocellular and renal cell carcinomas. CAM 5.2 may not react with some squamous cell carcinomas. Immunohistochemistry (IHC)
Carbonic Anhydrase IX (CA IX)Carbonic anhydrase IX (CAIX) is a cell surface transmembrane protein, which is predominantly found in the gastrointestinal tract and gall bladder. The glandular regions of normal colon are reported to be negative, but in the case of adenocarcinoma, the glands are positive. CAIX is also expressed in common epithelial tumors such as carcinomas of the esophagus, lung, colon, kidney, cervix, and non-small cell lung carcinoma (NSCLC). In breast carcinomas, CAIX expression is associated with malignant tissue. Expression of CAIX is absent in normal kidney, chromophobe carcinomas or oncocytomas; however, it is specifically expressed in clear cell renal carcinomas. Immunohistochemistry (IHC)
CD10CD10, also known as Common Acute Lymphocytic Leukemia Antigen (CALLA), is expressed in early lymphoid progenitors and normal germinal center cells. It is almost always present on the surface of precursor B-lymphoblastic and Burkitt lymphomas and much less frequently on precursor T-lymphoblastic leukemia-lymphoma. Many follicular lymphoma and some diffuse large B-cell lymphomas, along with multiple myeloma are positive. CD10 is also present on breast myoepithelial cells, bile canaliculi, fibroblasts and with especially high expression on the brush border of kidney and gut epithelial cells. CD10 is also a good marker of endometrial stomal sarcoma. Immunohistochemistry (IHC)
CD117 cKIT

CD117 (cKit) is a transmembrane receptor tyrosine kinase. It is expressed in many tissues and cells, such as tissue mast cells, skin basal cells, melanocytes, breast glandular epithelial cells, dermal sweat gland, esophageal glands, testicular and ovarian interstitial cells. Abnormal expression of cKit has been implicated in pathogenesis of myeloid leukemias. cKit expression has also been demonstrated in solid tumors including gastrointestinal stromal tumor (GIST), melanomas, breast carcinomas and small cell lung carcinoma. C-Kit pharmDXTM is indicated as an aid in the differential diagnosis of GIST. Accurate assessment of CD117 protein expression using cKIT testing is a critical factor in the diagnosis of GIST and is becoming increasingly important in clinical management, including the use of imatinib mesylate (Gleevec®) therapy.

Immunohistochemistry (IHC)
CD11cIn normal cells, CD11c is expressed on activated CD4/CD8+ T cells, granulocytes, lymphocytes, macrophages, and NK cells.

In diseased, cells, CD11c is detected on acute myeloid leukemia (AML)-M4 and M5, hairy cell leukemia, lymphoplasmacytic lymphoma (81%), small lymphocytic lymphoma (SLL), splenic lymphoma, Langerhans cell histiocytosis, sinus histiocytosis, psoriatic skin lesions, and some follicular lymphomas.
Immunohistochemistry (IHC)
CD123CD123 labels plasmacytoid dendritic cells and is useful in diagnosing neoplasms derived from these cells as well as reactive conditions, such as histiocytic necrotizing lymphadentis. Immunohistochemistry (IHC)
CD138CD138 (Syndecan-1) positively stains normal tissue including B-cell precursors and plasma cells. Positive staining in tumors includes myeloma, primary effusion lymphoma. CD138 negative staining comprises mature B-cells and lymphomas (even plasmacytoid lymphomas). Many carcinomas also express CD138. Immunohistochemistry (IHC)
CD14CD14 stains normal macrophages/monocytes, granulocytes (weak), Langerhans cells, dendritic cells, and B cells. Positive staining in diseased cells comprises B-cell chronic lymphocytic leukemia (B-CLL), follicular center cell lymphoma, diffuse large B cell lymphoma (DLBCL), and acute myeloid leukemia (AML)-M4/M5. Immunohistochemistry (IHC)
CD15CD15 (X-Hapten) plays a role in mediating phagocytosis, bactericidal activity, and chemotaxis. It is present on granulocytes, including neutrophils and eosinophils, and to a lesser degree on monocytes. CD15 is also expressed in Reed-Sternberg cells and some epithelial cells. CD15 antibody is useful in the identification of Hodgkin lymphoma. CD15 is occasionally expressed in large cell lymphomas of both B- and T- phenotypes. Immunohistochemistry (IHC)
CD163CD163 antigen is restricted in its expression to the monocytic/macrophage lineage. It is present on all circulating monocytes and most tissue macrophages except those found in the mantle zone and germinal centers of lymphoid follicles, interdigitating reticulum cells and Langerhans cells. Immunohistochemistry (IHC)
CD19CD19 recognizes a 95kD cell surface glycoprotein which is expressed by cells of the B-cell lineage and follicular dendritic cells. CD19 is a co-receptor of CD21and is an important signal transduction molecule which is involved in the regulation of B-lymphocyte development, activation and differentiation. CD19 may provide useful diagnostic information for the study of B-lymphoproliferative disorders. Immunohistochemistry (IHC)
CD1aAt least five CD1 genes (CD1a, b, c, d, and e) have been identified. CD1a is expressed on cortical thymocytes, Langerhans cells, and dendritic cells. It is absent on mature peripheral blood T-cells, but cytoplasmic expression is detected on activated T-lymphocytes. CD1a is found on a subset of T-lymphoblastic lymphoma-leukemia and cases of Langerhans cell histiocytosis. Immunohistochemistry (IHC)
CD2CD2, the E-rosette receptor, is an extremely broad T-cell marker. This antibody immunostains the vast majority of T-cells and a subset of natural killer (NK) - cell malignancies. Half of thymic B-cells are also CD2 positive. Immunohistochemistry (IHC)
CD20Normal cell expression of CD20 is found on most B-cells (after CD19 and CD10 expression, before CD21/22 expression and surface immunoglobulin expression) and expression is retained on mature B-cells until plasma cell development, as well as ollicular dendritic cells. In diseased cells, there is positive staining on most B-cell lymphomas, come pre-acute B lymphoblastic leukemia/ lymphoblastic lymphoma (B-ALL/LBL); lymphocyte predominant Hodgkin lymphoma, dimly expressed in T-cells (benign and neoplastic), and spindle cell thymomas. Rixtuximab treated patients may lose CD20 positivity in B cell lymphomas. Immunohistochemistry (IHC)
CD21CD21 (CR2, C3d receptor and EBV receptor) is expressed strongly on mature B-cells, follicular dendritic cells (FDC) and weakly on immature thymocytes and T-lymphocytes. In B-cell ontogeny, CD21 appears after the pre-B-stage, is maintained during peripheral B-cell development and is lost upon terminal differentiation into plasma cells. Immunohistological analysis of FDC in paraffin sections of Non-Hodgkin lymphoma (NHL) with this antibody demonstrates a nodular and usually dense and sharply defined FDC meshwork in follicular lymphomas and a loose, ill-defined FDC of varying size in some diffuse lymphoma types. Precursor B-cell lymphoma (lymphoblastic lymphomas), Burkitt lymphomas, plasmacytomas and hairy cell leukemias consistently lack CD21 expression. CD21 is expressed on follicular dendritic cell sarcoma. Immunohistochemistry (IHC)
CD22CD22 expression is restricted to normal and neoplastic B-cells and is absent from other hemopoietic cell types. In B-cell ontogeny, CD22 is first expressed in the cytoplasm of pro-B and pre-B-cells and on the surface as B-cells mature to become IgD+. It is not expressed by plasma cells. CD22 is found highly expressed in follicular, mantle and marginal zone B-cells, while germinal center B-cells are relatively weak. Its expression roughly parallels that of CD19. It is strongly expressed in hairy cell leukemia. Immunohistochemistry (IHC)
CD23CD23 is identical to low affinity IgE receptor found on B-cells. CD23 is expressed on a subpopulation of peripheral blood cells, B-lymphocytes and on EBV transformed B-lymphoblastoid cell lines. CD23 is most useful in distinguishing B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) from other entities and may remain present in CLL/SLL that has undergone large cell transformation. Immunohistochemistry (IHC)
CD25The interleukin-2 receptor is designated CD25. Originally isolated from T-lymphocytes, it is now known to be expressed on hairy cell leukemia and adult T-cell leukemia/lymphoma, classical Hodgkin lymphoma, and a subset of other peripheral T-cell lymphomas. Immunohistochemistry (IHC)
CD3The CD3 antigen is first detectable in early thymocytes and its appearance probably represents one of the earliest signs of commitment to the T-cell lineage. It has a cytoplasmic expression at early T-cell differentiation, then membranous expression. CD3 is the most specific T-cell antibody. CD3 is expressed in normal thymocytes, peripheral T-cells, NK cells, and Purkinje cells of cerebellum. In diseased cells, CD3 stains most T-cell lymphomas. Only rare B cell lymphomas may be positive for CD3. Immunohistochemistry (IHC)
CD30CD30 is a lymphocyte activation antigen, related to tumor necrosis factor. It is expressed in activated B-, T- and NK cells. Positive staining is seen in infectious mononucleosis, lymphocytes infected with HIV, HTLV-1, EBV, HHV8 or hepatitis B, Reed-Sternberg cells, anaplastic large cell lymphomas (90%), lymphomatoid papulosis, peripheral T-cell lymphomas, and embryonal cell tumors. Immunohistochemistry (IHC)
CD31CD31 is a 130kDa transmembrane glycoprotein that is shared by vascular lining cells, megakaryocytes and platelets. This marker is highly restricted to endothelial neoplasms among all tumors of the soft tissue and its sensitivity is excellent. 100% of angiosarcomas and hemangiomas are CD31 positive. However, Kaposi’s sarcoma (KS) is labeled more consistently by CD34 than by CD31. CD31 has also been used as a prognostic marker measuring tumor angiogenesis. CD31 also stains histiocytes. Immunohistochemistry (IHC)
CD33CD33 is a useful marker to identify cells of myeloid and monocytic lineage, leukemias and myeloproliferative neoplasms derived from these cells. Immunohistochemistry (IHC)
CD34CD34, a single chain transmembrane glycoprotein, is selectively expressed on human lymphoid and myeloid hematopoietic progenitor cells and endothelial cells. CD34 antibody labels many gastrointestinal stromal tumors (GIST), dermatofibrosarcoma protuberans, solitary fibrous tumor and a subset of sarcomas. CD34 staining has been also used to measure angiogenesis. Immunohistochemistry (IHC)

CD35 antigen is a transmembrane protein of 160-250 kDa that binds complement components C3b and C4b. It mediates phagocytosis by neutrophils and monocytes. CD35 is found on erythrocytes, B-cells, a subset of T-cells, monocytes, macrophages cultured in vitro, neutrophils, eosinophils, glomerular podocytes and follicular dendritic cells. CD35 antibody is useful in the diagnosis of mucosa-associated lymphoid tissue (MALT) lymphoma and in the study of inflammatory disorders. It also labels follicular dendritic cell sarcoma.

Immunohistochemistry (IHC)
CD38CD38 is a transmembrane protein that is highly expressed on thymocytes. It is also present on activated T-cells and terminally differentiated B-cells (plasma cells). Other reactive cells include NK cells, monocytes, macrophages and dendritic cells. CD38 may be detected on cells from multiple myeloma, acute lymphoblastic leukemia (ALL, B and T) and some acute myeloid leukemia (AML). Immunohistochemistry (IHC)
CD4CD4, a single chain transmembrane glycoprotein, is found on a T-cell subset (helper/inducer). It is also present on a variety of monocyte-derived cells, including Langerhans and other dendritic cells. The CD4 epitope is absent from immature thymocytes and is expressed during T-cell development. Precursor T-lymphoblastic lymphomas are therefore variable in their expression of CD4, but most mature T-cell lymphomas are positive, with the exception of aggressive NK-cell leukemia, extranodal NK-cell lymphoma, gamma delta T-cell lymphomas, and enteropathy-type T-cell lymphoma. Immunohistochemistry (IHC)
CD42bCD42b stains normal platelets, megakaryocytes, and megakaryoblasts. In diseased cells, blasts in transient myeloproliferative disorder are positively stained. CD42b is used in diagnosis of acute myeloid leukemia (AML)-M7, distinguishing AML-M7 (CD42b+) from acute myelosis with myelofibrosis (usually CD42b negative). Immunohistochemistry (IHC)
CD43CD43 (leukosialin, sialophorin, or leukocyte sialoglycoprotein) is a cell surface glycoprotein that is expressed on all thymocytes, T-cells, and cells of myeloid lineage. CD43 antibody can be useful in the diagnosis of T-cell lymphoma and a subset of B-cell lymphoma. CD43 expression in lymphomas is highly correlated with CD5; thus, most T-cell malignancies and a group of small lymphocyte B-cell malignancies (CLL/SLL, mantle cell lymphoma, and prolymphocytic leukemia (PLL)) are often positive, whereas follicular lymphoma is rarely positive. CD43 is also positive in about 50% of cases of Burkitt lymphoma. Immunohistochemistry (IHC)
CD44The CD44 family of glycoproteins exists in a number of variant isoforms, including hematopoietic variant (CD44s) and epithelial cells variant (CD44v). While many human tumors express CD44, a positive correlation between increased CD44 expression and tumor progression has been demonstrated in only some. The most practical application of CD44 immunostaining at present is the discrimination of urothelial transitional call carcinoma-in-situ from non-neoplastic changes in the urothelium. Immunohistochemistry (IHC)
CD45 (LCA)CD45 (Leukocyte Common Antigen, LCA) is comprised of at least four isoforms (CD45RA, CD45RB, CD45RC and CD45RO) of membrane glycoproteins. CD45 is expressed on hematopoietic cells (human leukocytes, including lymphocytes, monocytes, and eosinophils), but is absent on normal and malignant non-hematopoietic tissues. Immunohistochemistry (IHC)
CD45ROCD45RO (an isoform of leukocyte common antigen) reacts with mature activated T-cells, most thymocytes, and a sub-population of resting T-cells within both CD4 and CD8 subsets. CD45RO antibody marks many T-cell lymphomas but also identifies granulocytes, histiocytes and some B-cells. It rarely stains B-cell lymphomas. Immunohistochemistry (IHC)
CD5CD5, a transmembrane protein, is found on most thymocytes and immature peripheral T-cells. It stains normal B-cells of mantle zone of spleen and lymph nodes, B-cells in peritoneal and pleural cavities, and almost all T-cells. In a fetus, most B-cells in spleen and cord blood are CD5 positive. It stains B-cell chronic lymphocytic leukemia/ small lymphocytic leukemia (CLL/SLL), mantle cell lymphoma (MCL), hairy cell leukemia (HCL), most T-malignancies, and most thymic carcinomas. CD5 is usually negative in spindle cell thymoma. Immunohistochemistry (IHC)
CD56CD56 recognizes two proteins of the neural cell adhesion molecule, the basic molecule expressed on most neuroectodermally-derived cell lines, tissues and neoplasms (e.g. retinoblastoma, medulloblastomas, astrocytomas, and neuroblastomas). It is also expressed on some mesodermally-derived tumors (rhabdomyosarcoma) and on natural killer cells. CD56 can be used as a marker for NK cell neoplasms. Some benign and malignant plasma cells are also positive. CD56 is often positive in neuroendocrine carcinomas. Immunohistochemistry (IHC)
CD57CD57 is expressed on subpopulations of peripheral blood mononuclear cells, NK active cells and T-cells. Hematopoietic malignancies that are CD57+ include a minority of T-lymphoblastic leukemias, roughly three quarters of the indolent T-cell large granular lymphocytic leukemias, and a small portion of NK-cell lymphomas. It can be used to highlight small lymphoid cells in nodular lymphocytic predominant Hodgkin lymphoma. Immunohistochemistry (IHC)
CD61CD61 (GPIIIa) is a glycoprotein found on megakaryocytes, platelets, and their precursors. CD61 antigen plays a role in platelet aggregation and also as a receptor for fibrinogen, fibronectin, von Willebrand factor, and vitronectrin. This antibody is useful in detecting neoplastic platelet precursors, normal platelets, and most cases of megakaryocytic leukemias. Immunohistochemistry (IHC)
CD68CD68 is an antibody directed against lysosomes. It is important for identifying macrophages in tissue sections. It stains macrophages in a wide variety of human tissues, including Kupffer cells and macrophages in the red pulp of the spleen, lamina propria of the gut, lung alveoli, and bone marrow. This antibody reacts with myeloid precursors and peripheral blood granulocytes. It shows strong granular cytoplasmic staining of chronic and acute myeloid leukemia and also reacts with true histiocytic neoplasia. It also stains granular cell tumors and some cases of melanoma, renal cell carcinoma, and pleomorphic sarcoma. Tumors of lymphoid origin are usually not stained. Immunohistochemistry (IHC)
CD7CD7 is expressed on the majority of immature and mature T-lymphocytes and T-cell leukemia. It is also found on natural killer cells, and a small subpopulation of normal and malignant B-cells. CD7 antibody can be useful for detection of T-cell leukemias and myeloid leukemias. CD7 expression is often lost in mycosis fungoides. Immunohistochemistry (IHC)
CD71CD71 is useful in identifying erythroid precursors with no interference from mature erythrocytes and also in the determination of erythroid leukemia, benign erythroid proliferative disorders, and myelodysplastic syndrome. Immunohistochemistry (IHC)
CD79aCD79a first appears at the pre B-cell stage and persists until the plasma cell stage where it is found as an intracellular component. CD79a is found in the majority of acute leukemias of precursor B-cell type, B-cell lines, B-cell lymphomas, and in some myelomas. It is not present in myeloid cells or T-cells. Immunohistochemistry (IHC)
CD8CD8 is a T-cell marker for the detection of cytotoxic/suppressor T-cells. CD8 is also detected on NK cells, most thymocytes, a subpopulation of null cells, and bone marrow cells. This antibody is useful in evaluating T-cell lymphomas. Immunohistochemistry (IHC)
CD99CD99 (MIC2 gene product, E2) antigen is strongly expressed by Ewing sarcoma cells, primitive peripheral neuroectodermal tumors, and lymphoblastic leukemia/lymphoma. Immunohistochemistry (IHC)
CDK4Among cyclin/CDK proteins, CDK4 and cyclin D1 are the most frequently activated by somatic genetic alterations in multiple tumor types. CDK4 antibody assists in distinguishing atypical lipomatous tumor well-differentiated liposarcoma (WDL) (positive) from benign adipocytic neoplasms (negative). Immunohistochemistry (IHC)
CDX2CDX2 is an intestine specific transcription factor that regulates both the proliferation and differentiation of intestinal epithelial cells. It is expressed in the nuclei of epithelial cells throughout the intestine, from duodenum to rectum. The CDX2 protein is expressed in primary and metastatic colorectal carcinomas and has also been demonstrated in the intestinal metaplasia of the stomach and intestinal-type gastric cancer. It is not expressed in the normal gastric mucosa. CDX2 may be used in identifying metastatic carcinoma of colonic or other gastrointestinal tract origin in the setting of an unknown primary tumor. Immunohistochemistry (IHC)
CDX2/CK7 Double StainCDX2 is a transcription factor expressed in the nuclei of epithelial cells throughout the intestine, from duodenum to rectum. The CDX2 protein is expressed in primary and metastatic colorectal carcinomas and has also been demonstrated in the intestinal metaplasia of the stomach and intestinal-type gastric cancer. It is not expressed in the normal gastric mucosa. Cytokeratin 7 is a basic cytokeratin and is expressed in epithelial cells of ovary, lung, and breast, but not of the colon or gastrointestinal tract. This antibody cocktail of CDX2 and CK7 can be used simultaneously to distinguish stomach and colon cancers from breast, lung, and ovarian cancers. Immunohistochemistry (IHC)
CEA (Mono)Carcinoembryonic antigen (CEA) is usually demonstrated as a linear labeling of the apical poles of cells lining the glandular lumen and occasionally as weak staining near the apex of normal colonic epithelial cells. Tumors tend to display an increased cytoplasmic staining. In specific cases, CEA can be useful in tumor diagnosis. Pancreatic carcinomas, testicular tumors, gallbladder neoplasms and granular cell myoblastomas all stain positive for CEA, while malignant tumors of brain, prostate, skin, lymphoreticular tissues, hepatocellular carcinomas, esophageal squamous cell carcinomas and mesothelioma fail to stain for CEA. Immunohistochemistry (IHC)
CEA (Poly)Polyclonal carcinoembryonic antigen (CEA) antibody stains a larger percentage of cholangiocarcinomas compared to hepatocellular carcinomas. Approximately 95% of olangiocarcinomas are stained diffusely and strongly with polyclonal CEA, whereas show a canalicular staining pattern with this antibody. Immunohistochemistry (IHC)
Chloroacetate Esterase (CAE)

Cytochemical stain.

Immunohistochemistry (IHC)
Chromogranin AChromogranin is present in several elements of the diffuse neuroendocrine system (DNES), including anterior pituitary, thyroid perifollicular C cells, parathyroid chief cells, pancreatic islet cells, intestinal enterochromaffin cells and tumors derived from these cells. Chromogranin immunoreactivity was also seen in thymus, spleen, lymph nodes, fetal liver, neurons, the inner segment of rods and cones, the submandibullar gland and the central nervous system. This marker is useful in evaluating neuroendocrine tumors. Immunohistochemistry (IHC)
CK 10/13 (Cytokeratin 10/13)Cytokeratins 10 and 13 are intermediate-size, acidic type I cytokeratins (molecular mass of 56.5 kDa). CK10/13 cocktail is expressed in all suprabasal cells of normal stratified squamous epithelium, although it is absent in the basal layer. CK10/13 expression can be lost in dysplastic lesions of the stratified squamous epithelium. Immunohistochemistry (IHC)
CK HMW (CK903/34BE12)CK903 (34betaE12) is a high molecular weight cytokeratin present in all squamous epithelium and their carcinomas. This antibody recognizes cytokeratins 1, 5, 10 and 14 that are found in complex epithelia. There has been no reactivity with cells derived from simple epithelia, mesenchymal tumors, lymphomas, melanomas, neural tumors and neuroendocrine tumors. One useful application is the identification of the basal cell layer in prostate tissue in the determination of carcinoma. Immunohistochemistry (IHC)
CK HMW/CK LMW Double StainThis cytokeratin cocktail can be useful in differentiation of the squamous cell carcinomas and adenocarcinomas. The 34bE12 clone recognizes cytokeratin (CK) 1, 5, 10 and 14. It is reactive with stratified epithelia, myoepithelial and basal cells of prostate and breast, and it stains squamous carcinomas and adenosquamous carcinomas (brown). Clone 5D3 recognizes cytokeratin (CK) 8 and 18 of all simple and glandular epithelium and adenocarcinomas (red). Immunohistochemistry (IHC)
CK OSCARAnti-cytokeratin clone OSCAR (CK OSCAR) demonstrates a broad spectrum of cytokeratin reactivity. In normal tissues, OSCAR is reactive with most epithelial types, including bile ducts and hepatocytes in liver, bladder epithelium, breast ducts, bronchial epithelium, endometrium, intestinal epithelium of stomach, duodenum, ileum, colon, rectum, pancreas, ovarian epithelium, pancreatic acini, pituitary acini, pneumocytes, prostate, thyroid, skin (positive on the basal layer and negative on the superficial layers of squamous epithelium), and apocrine and sweat glands. In tumors, OSCAR is reactive with most carcinomas, including breast, transitional cell (TCC), renal cell (RCC), lung adenocarcinoma, lung small cell, lung squamous cell, endometrial, prostate, ovarian, hepatocellular (HCC), colorectal CA, stomach and thyroid. It is negative in certain normal tissues, including brain, lymphocytes and all cells of hematolymphoid origin, muscle, brain, nerves, endothelium and in certain tumors including most melanomas, sarcomas, lymphomas, primitive neuroectodermal tumors (PNET)/Ewings and gastrointestinal stromal tumors (GIST). Positivity has been seen on some dendritic cells in lymph nodes, some endothelia, and some muscle cells. Immunohistochemistry (IHC)
CK14 (Cytokeratin 14)Cytokeratin 14 (CK14) belongs to the type A (acidic) subfamily of high molecular weight keratins and exists in combination with keratin 5. CK14 has been studied as a prognostic marker in breast cancer. CK14 distinguishes stratified epithelial cells from simple epithelial cells and has been reported useful in the identification of squamous cell carcinomas. Immunohistochemistry (IHC)
CK17Cytokeratin 17 (CK17) is an effective marker to distinguish myoepithelial cells from luminal epithelium of various glands (mammary, sweat, salivary, bronchial, tracheal, laryngeal, esophageal) and benign from malignant forms of tumors, e.g. mammary gland tumors. Predominant expression of CK17 is the characteristic feature of basal cell carcinomas. It is often positive in carcinomas of pancreatic or biliary origin. Immunohistochemistry (IHC)
CK18 (Cytokeratin 18)Cytokeratin 18 (CK 18), a 45kDa protein, belongs to the acidic type of cytokeratins, and is typically expressed in simple, nonstratified epithelia. However, CK 18 is also expressed in basal and superficial cells of transitional epithelium, as well as in the luminal/secretory cells of complex epithelia. Immunohistochemistry (IHC)
CK19Cytokeratin 19 (CK19) is a member of the type I acidic subfamily of keratins. It is expressed in various different human tissues. CK19 labels ductal and glandular epithelia, prostatic epithelia, and non-keratinizing squamous epithelia. This antibody is useful in the diagnosis of breast and cervical carcinoma. CK19 is not expressed in hepatocytes, therefore, antibody to CK19 is also useful in the distinction of liver metastasis from hepatocellular carcinomas. Immunohistochemistry (IHC)
CK20Cytokeratin 20 (CK20) positivity is seen in the majority of adenocarcinomas of the colon, mucinous ovarian carcinomas, transitional cell, and Merkel cell carcinomas, and frequently in adenocarcinomas of the stomach, bile system and pancreas. CK7/CK20 immunostaining patterns may be helpful in separating pulmonary from colonic adenocarcinomas. Immunohistochemistry (IHC)
CK5/6D5/16 B4 clone of CK5/6 antibody reacts strongly with cytokeratins 5 and 6. Cytokeratin 5/6 have been found valuable for the distinction between low differentiated squamous cell carcinoma and adenocarcinoma. It labels mesothelioma, and epithelial basal cells in prostate and tonsil. No reactivity with other mesodermally derived tissues, such as muscle and connective tissues, has been observed. Anti-CK 5/6 has also been found useful in the differential diagnosis of atypical proliferations of the breast. Immunohistochemistry (IHC)
CK7Cytokeratin 7 (CK7) antibody reacts with proteins that are found in most ductal, glandular and transitional epithelium of the urinary tract and bile duct epithelial cells. CK7 distinguishes between lung and breast epithelium that stain positive, and colon and prostate epithelial cells that are negative. It also reacts with many benign and malignant epithelial lesions, e.g. adenocarcinomas of the ovary, breast and lung. Transitional cell carcinomas are positive and most prostate cancers are negative. This antibody does not recognize other intermediate filament proteins. Immunohistochemistry (IHC)
cMETThe cMET tyrosine kinase receptor, normally expressed by epithelial cells, is overexpressed and amplified in a variety of human tumors, including non-small cell lung carcinoma (NSCLC). High levels of intratumor cMET expression have been associated with a more aggressive biology and a worse prognosis in NSCLC. Engelman et al. reported that cMET amplification induced resistance to gefitinib in a gefitinib-sensitive lung cancer cell line. Moreover, cMET inhibition with a cMET tyrosine kinase inhibitor (PHA-665,752) restored gefitinib sensitivity. Immunohistochemistry (IHC)
CMV (Cytomegalovirus) by IHCCytomegalovirus (CMV) is an opportunistic pathogen infecting lung, kidney, gut and other organs in situations where an individual is immunologically immature, such as the fetus and neonate. Infection also occurs in immunosuppressed patients, e.g. transplant patients, patients undergoing chemotherapy and HIV infected patients. Immunohistochemistry (IHC)
cMyccMyc protein is a transcription factor localized to the nucleus of the cell. Amplification of the cMyc gene has been found in several types of human tumors.

cMyc is amplified in 20-30% of breast cancer cases and is associated with HER-2 amplification and poor outcome. In Burkitt’s lymphoma, 90% of tumors have translocation of cMyc or variants. cMyc protein (>50%) is seen in a subset of cases of diffuse large B-cell lymphoma (DLBCL) and is correlated with Myc rearrangement. It is also positive in radiation-associated angiosarcoma.

Immunohistochemistry (IHC)
Collagen IVCollagen IV is a major constituent of the basement membranes along with laminins and enactins. In kidney, the antibody reacts with glomerular and tubular basement membranes, parts of the mesenchymal matrix, and the Bowman’s capsule. It also reacts with the basal lamina of capillaries and basement membranes in a variety of tissues. Antibody to collagen IV is useful in evaluating neural neoplasms. Immunohistochemistry (IHC)
Colloidal IronSpecial stain. Immunohistochemistry (IHC)
Congo Red

Special stain.

Immunohistochemistry (IHC)
Copper StainSpecial stain. Immunohistochemistry (IHC)
COX2Cyclooxygenase-2 (COX-2) plays a role in tumorigenesis through stimulating epithelial cell proliferation, inhibiting apoptosis, stimulating angiogenesis, enhancing cell invasiveness, mediating immune suppression, and by increasing the production of mutagens. COX-2 is expressed in breast cancer, transitional cell carcinoma of the bladder, high-grade endometrioid carcinoma, and ovarian cancer. Overexpression of COX-2 is associated with poor prognosis in cervical cancers after radiation and concurrent chemotherapy. Immunohistochemistry (IHC)
cRELInactive cREL resides in the cytoplasm and translocates to the nucleus upon activation. Strong, homogeneous nuclear cREL staining has been observed in primary mediastinal large B-cell lymphoma whereas nuclear cREL expression is more variable in other forms of diffuse large B-cell lymphoma (DLBCL). Evaluation of cREL nuclear expression combined with germinal center B-cell (GCB) and non-GCB phenotyping by IHC may improve patient risk stratification in DLBCL. Immunohistochemistry (IHC)

CXCL13 is useful marker in the diagnosis of angioimmunoblastic T-cell lymphoma

Immunohistochemistry (IHC)
D240D2 40 identifies a 40kDa O-linked sialoglycoprotein expressed by a variety of tissues, including fetal testes and testicular germ cell tumors. Anti-D2 40 has also been demonstrated to label lymphatic endothelium whereas it is unreactive with vascular endothelium. In neoplastic tissue, immunostaining of lymphatic endothelium by anti-D2 40 can be useful in identifying lymphatic invasion of primary tumors. It is also often positive on sarcomatoid malignant mesothelioma. Immunohistochemistry (IHC)
DBA.44This antibody reacts with a subset of B-cells in the mantle zone and some immunoblasts outside the follicle. It reacts with most hairy cell leukemia cases. This antibody shows strong positive staining in some high grade B-cell lymphoma cases. Immunohistochemistry (IHC)
DesminDesmin is an intermediate filament protein of both smooth and striated muscles. Antibody to desmin reacts with striated (skeletal and cardiac) as well as smooth muscle cells. Anti-desmin antibody is useful in identification of tumors of myogenic origin. It reacts with leiomyosarcomas (smooth muscle) as well as rhabdomyosarcomas (striated muscle). Immunohistochemistry (IHC)
DOG1DOG1 is a cell surface protein of unknown function selectively expressed in gastrointestinal stromal tumors (GIST). Among GIST cases with Kit mutations the DOG1 antibody identified 11% more cases than c-Kit antibody. DOG1 identifies the vast majority of both cKIT negative and Platelet-derived Growth Factor Receptor Alpha (PDGFRA) mutated GIST cases that may still benefit from imatinib mesylate (Gleevec®), an inhibitor of the Kit tyrosine kinase. In addition, DOG1 immunoreactivity is seen in fewer cases of mesanchymal, epithelial tumors and melanomas when compared with cKIT. The use of this highly sensitive and specific novel marker will increase the accuracy of GIST diagnosis. Immunohistochemistry (IHC)
DPC4The gene DPC4 (deleted in pancreatic carcinoma 4, also called SMAD4) was identified in 18q21.3 This gene is frequently mutated and deleted in pancreatic carcinomas (55%) and less frequently (20 - 22%) in colon carcinomas. Loss of expression is specific for pancreatic malignancy (in-situ or invasive) vs. benign process, particularly helpful in biopsies. Immunohistochemistry (IHC)
E-CadherinE Cadherin is an adhesion protein that is expressed in cells of epithelial lineage. It stains positively in glandular epithelium, as well as adenocarcinomas of the lung, G.I. tract and ovary. It is useful in distinguishing adenocarcinoma from mesothelioma. It is also positive in some thyroid carcinomas. Breast carcinomas with ductal and lobular features show two staining patterns: (1) complete or almost complete lack of membrane staining in lobular carcinomas and (2) uniform membrane expression throughout the tumor in ductal carcinomas. Immunohistochemical detection of ECadherin expression can be a useful diagnostic tool for the differentiation of ductal and lobular carcinomas of the breast. Immunohistochemistry (IHC)
EBV (LMP1)This antibody reacts strongly with Epstein Barr Virus (EBV)-positive lymphoblastoid cell lines and EBV infected B-cell immunoblasts in infectious mononucleosis. It also reacts with some EBV-associated neoplasms, particularly EBV-associated Hodgkin lymphoma. Immunohistochemistry (IHC)
EGFREpidermal Growth Factor Receptor (EGFR) overexpression can occur in a variety of tumor types, including breast, prostate, ovarian, brain, lung and predominantly squamous cell carcinomas. Tumors that express EGFR are associated with a poor prognosis and a shorter disease-free survival. Most colon carcinomas will show expression of EGFR in more than 1% of the invasive tumor cells. Patients whose tumor expresses EGFR are eligible for cetuximab therapy although the response to therapy is independent of the intensity or percentage of cells staining. Immunohistochemistry (IHC)
EGFR (E746-A750del specific)Epidermal Growth Factor Receptor (EGFR) is a 170 kDa transmembrane receptor tyrosine kinase that belongs to the HER/ErbB protein family. Somatic mutations in the tyrosine kinase domain of EGFR are present in a subset of lung adenocarcinomas. Two types of mutations account for approximately 90% of mutated cases: a specific point mutation, L858R, which occurs in exon 21 and short in-frame deletions in exon 19. A common lesion in exon 19 is the deletion of E746-A750, although other variants occur. IHC-based EGFR E746-A750del specific antibody is designed to detect deletion of E746-A750 in exon 19. Deletion in exon 19 is associated with response of non-small cell lung carcinoma (NSCLC) to gefitinib or erlotinib monotherapy. Immunohistochemistry (IHC)
EGFR (L858R mutant specific)Epidermal Growth Factor Receptor (EGFR) is a 170 kDa transmembrane receptor tyrosine kinase that belongs to the HER/ErbB protein family. Somatic mutations in the tyrosine kinase domain of EGFR are present in a subset of lung adenocarcinomas. Two types of mutations account for approximately 90% of mutated cases: a specific point mutation (L858R) which occurs in exon 21 and short in-frame deletions in exon 19. IHC-based EGFR L858R mutant specific antibody is designed to detect the L858R missense mutation associated with response of non-small cell lung carcinoma (NSCLC) to gefitinib or erlotinib monotherapy. Immunohistochemistry (IHC)
eIF4EeIF4E is a key regulator of translation of many cancer-related transcripts and its expression is altered in various cancers and has been associated with worse survival. High expression of eIF4E is associated with adverse tumor characteristics and predicts poor breast cancer-specific survival. Immunohistochemistry (IHC)
Elastic StainSpecial stain. Immunohistochemistry (IHC)
EMAEpithelial Membrane Antigen (EMA) antibody stains normal and neoplastic cells from various tissues, including mammary epithelium, sweat glands and squamous epithelium. Hepatocellular carcinoma, adrenal carcinoma and embryonal carcinomas are consistently EMA negative, therefore, keratin positivity with negative EMA favors one of these tumors. EMA is frequently positive in meningioma, which can be useful when distinguishing it from other intracranial neoplasms, e.g. Schwannomas. The absence of EMA can also be of value since negative EMA is characteristic of tumors such as adrenal carcinoma, seminomas, paraganglioma and hepatoma. Immunohistochemistry (IHC)
EREstrogen Receptor (ER) belongs to a superfamily of nuclear hormone receptors and is expressed in about 85% of invasive breast cancers. There are two known isoforms of estrogen receptor, ERα and ERß. It is a weak prognostic factor but a strong predictive factor for response to endocrine therapies, both in adjuvant and metastatic settings. The primary indication to assess ER in breast cancer is to predict response to hormonal therapies such as tamoxifen, other selective estrogen receptor modulators (SERMs) and aromatase inhibitors. In univariate analysis, moderate to strong staining in even 1% of the invasive tumor cells is associated with significant improvement in disease-free survival compared to those patients whose tumor lacks ER expression. Immunohistochemistry (IHC)
ERCC1The Excision Repair Cross-Complementing Rodent Repair Deficiency, Complementation Group 1 (ERCC1) polypeptide is required for nucleotide excision repair (NER) of damaged DNA. Elevated levels of ERCC1 have also been reported in cisplatin-resistant cells. Immunohistochemistry (IHC)
ERGERG oncoprotein expression has been shown to be a highly specific marker for prostate cancer. Given the lack of ERG expression in a wide variety of normal epithelial tissues and tumors, detection of ERG by IHC is a valuable tool for diagnosing prostate cancer or determining prostatic origin. ERG is also a highly specific and sensitive marker of endothelial cells and vascular tumors. Immunohistochemistry (IHC)
Factor VIII RAFactor VIII-related antigen is a component of Factor VIII complex. Factor VIII-related antigen is one of the available immunohistochemical markers of endothelial cells. It has also been demonstrated in platelets and megakaryocytes. IHC staining of Factor VIII-related antigen is useful for diagnosis of vascular neoplasms and for identification of vascular invasion by neoplasms. Immunohistochemistry (IHC)
Factor XIIIaFactor XIIIa is a dermal dendrocyte marker and shows variable reaction with these types of tumors. It can be used for histiocytic phenotyping and has been reported to mark capillary hemangiomas and tumors of the central nervous system. Factor XIIIa has also been used with CD34 to differentiate between dermatofibroma and dermatofibrosarcoma protuberans. Immunohistochemistry (IHC)
FascinHuman fascin is a highly conserved actin-bundling protein. It is expressed predominantly in dendritic cells. Lymphoid cells, myeloid cells and plasma cells are negative for staining. However, Reed-Sternberg cells in Hodgkin lymphoma are positive for fascin staining. Epstein-Barr virus may induce expression of fascin in B-cells. Immunohistochemistry (IHC)
Fite (Leprosy) StainSpecial stain. Immunohistochemistry (IHC)
FLi-1Friend leukemia integration (FLI1) is a nuclear transcription factor and has been reported as the first nuclear marker of endothelial differentiation. FLI1 labels hemangiomas, angiosarcomas, Kaposis sarcoma, Ewings and Merkel cell carcinoma.

FLI1 is expressed in normal endothelial cells, megakaryocytes, normal breast epithelia.

Immunohistochemistry (IHC)
Fontana MassonSpecial stain. Immunohistochemistry (IHC)
FOXP1FOX P1 (Forkheadbox-P1) is a transcription factor widely expressed in normal tissues. Its expression is commonly deregulated in malignancies. FOX P1 is differentially expressed in resting and activated B cells. FOX P1 expression has been demonstrated in a subset of diffuse large B-cell lymphomas (DLBCL) and is more common in the non-germinal center (non-GC), activated B-cell type. Loss of FOX P1 expression has been correlated with a poor prognosis in solid tumors, such as breast cancer. In contrast, high level expression of smaller isoforms of the FOX P1 protein identifies high risk patients with DLBCL. The study demonstrated a correlation between strong nuclear positivity and poor prognosis in a subset of patients with BCL2-positive, [t(14;18)]-negative, non-GC DLBCL. Immunohistochemistry (IHC)
FOXP3FOX P3 is expressed at a high level in CD25 positive/CD4 positive regulatory T cells, at a low level in CD4 positive/CD25 negative cells, and is absent in CD4 negative/CD8 positive T cells. FOX P3 may be a master regulatory gene and a more specific marker of regulatory T cells than other T cells. Immunohistochemistry (IHC)
FSHFollicle Stimulating Hormone (FSH) is a pituitary hormone involved in the maturation of ovarian follicles and estrogen secretion in females. In the pituitary gland, FSH is produced by gonadotrophs. In males, FSH stimulates the secretion of testosterone. This antibody is used in the identification of FSH in pituitary adenomas. Immunohistochemistry (IHC)
Galectin 3Galectins are a structurally-related family of proteins; 14 different galectins have been characterized. They are cytoplasmic proteins and can be translocated into the nucleus. Gal-3 has been found overexpressed in most malignant thyroid neoplasms. However, it was not detectable in normal and non-malignant tissue. Galactin 3 is a useful marker to differentiate benign from malignant (Calactin-3 positive) thyroid neoplasms. Immunohistochemistry (IHC)
GastrinGastrin, a polypeptide hormone, occurs naturally in three forms: gastrin-14, gastrin-17 and gastrin-34. This antibody labels gastrin or gastrin-analogue producing cells in gastrin-secreting tumors and G cell hyperplasia. Immunohistochemistry (IHC)
GATA3GATA3 (GATA binding protein 3) is a member of the GATA family of transcription factors. Among several other roles, GATA3 is involved in luminal cell differentiation in the mammary gland and appears to control a set of genes involved in the differentiation and proliferation of breast cancer. The expression of GATA3 is associated with the expression of estrogen receptor-alpha (ER) in breast cancer. GATA3 has been shown to be a novel marker for bladder cancer. GATA3 stains almost all of urothelial carcinomas, but stained no prostate or renal carcinomas. Immunohistochemistry (IHC)
GCDFP15This antibody is specific to a 15kDa monomer protein called Gross Cystic Disease Fluid Protein-15 (GCDFP-15). GCDFP15 is expressed in apocrine epithelia, lacrimal, ceruminous and Moll’s glands, as well as in numerous serous cells of the submandibular, tracheal, bronchial, sublingual and minor salivary glands. It can be of use in the identification of breast carcinoma, salivary duct carcinoma and apocrine epithelia. Immunohistochemistry (IHC)
GCET1The GCET1 gene codes for a serpin expressed in germinal center (GC) B-cells. GCET1 is highly restricted to a subset of GC B-cells and GC-derived lymphomas. It is preferentially expressed in follicular lymphoma (FL) and diffuse large B-cell lymphoma (DLBCL) with GC B-cell differentiation. Immunohistochemistry (IHC)
GFAPGlial Fibrillary Acidic Protein (GFAP) is the major protein found in astrocytes and its expression is evidence of astroglial origin and differentiation. Gliomas are the most common cerebral neoplasm in adults and include astrocytomas, oligodendrogliomas and glioblastomas. It can also be demonstrated in ependymal cells, ependymomas, subependyomas, glioblastomas, mixed central nervous system neoplasms and gangliomas. It is detected in immature but not mature oligodendrocytes and neurons. Anti-GFAP antibodies do not cross-react with neurons, fibroblasts or muscle cells. Anti-GFAP antibodies are useful in differentiating primary gliomas from metastatic lesions in the brain and for documenting astrocytic differentiation in tumors outside the central nervous system. Immunohistochemistry (IHC)

Growth Hormone (GH) is produced by the somatotroph cells in the pituitary. This marker is a useful in classification of pituitary tumors and the study of pituitary disease (acromegaly).

Immunohistochemistry (IHC)
Giemsa for sectionsSpecial stain. Immunohistochemistry (IHC)
GlucagonGlucagon antibody is used for the identification of tumors and hyperplasias of pancreatic islets. This antibody labels A cells of the endocrine mammalian pancreas. It reacts with glucagon in a large number of mammalian species. Immunohistochemistry (IHC)
GLUT1Glucose transporter 1 (GLUT1) facilitates the transport of glucose across the plasma membranes of mammalian cells. GLUT-1 is expressed in many human tissues including those of the colon, lung, stomach, esophagus and breast. Overexpression of GLUT1 is associated with aggressive behavior in some cancers, including breast, renal, and bladder carcinoma. Expression of GLUT1 can help distinguish malignant mesothelioma from reactive mesotholial proliferations. Immunohistochemistry (IHC)
Glutamine Synthetase

Glutamine synthetase (GS) is strongly expressed in a majority of hepatocellular carcinoma, including cases of early HCC and low grade HCC.

Immunohistochemistry (IHC)
Glycophorin AGlycophorin A (sialoglycoprotein alpha) is one of two transmembrane proteins exposed on the outer surface of normal human erythrocytes. This monoclonal antibody reacts with an epitope located on the extracellular domain of glycophorin A and does not cross-react with glycophorin D (glycophorin delta). In normal human erythrocytes, glycophorin A is expressed during all stages of differentiation, from the normoblast to the mature erythrocyte. Once maximally expressed, the quantity of glycophorin A in each red blood cell remains constant. Glycophorin A has also been located in the blast cells of cases of erythroleukemia. Cases of acute lymphoblastic and myeloblastic leukemia are not reactive. Immunohistochemistry (IHC)
Glypican-3A useful marker to differentiate between benign (negative) and malignant (positive) liver diseases (HCCs). Immunohistochemistry (IHC)
Gram Stain (Brown & Hopp modification)Special stain. Immunohistochemistry (IHC)
Granzyme BGranzyme B antibody labels activated human cytotoxic T lymphocytes (CTL) and natural killer (NK) cells. This marker can be a useful tool for the identification of anaplastic large cell lymphoma, large granular lymphocytic leukemias, hepatosplenic T-cell lymphomas, intestinal T-cell lymphomas, NK-like T-cell lymphomas, NK-cell lymphomas, nasal T/NK-cell lymphomas, and subcutaneous panniculitic T-cell lymphomas of T or NK phenotype. Immunohistochemistry (IHC)
Grocott Methanamine Silver (GMS)Special stain. GMS (Grocott Methenamine-Silver Nitrate) Fungus Stain is used to demonstrate fungal organisms in tissue sections. Immunohistochemistry (IHC)
GST PiGlutathione S Transferase Pi (GSTpi) is a cytosolic enzyme that catalyzes the conjugation of toxic compounds to glutathione for transport out of the cell. Increased expression of GSTp has been demonstrated to show increased resistance to alkylating agents, such as cyclophosphamide, ifosphamide, and melphalan. GSTp is widely distributed throughout the body and has been identified in epithelial elements of thyroid, urinary, digestive track, and hepatic bile ducts. Adenocarcinomas of the stomach, kidney, uterus and ovary, as well as squamous cell tumors of the head and neck, melanomas, and carcinoid tumors of the lung all demonstrate reactivity with this antibody. Immunohistochemistry (IHC)
H. PyloriThis antibody reacts with H. pylori on the surface and in the cytoplasm of epithelial cells of stomach biopsies. Studies have shown that H. pylori plays an important role in the etiology of chronic active gastritis and the development of peptic ulcer disease. Immunohistochemistry can provide rapid detection of this bacterium. Immunohistochemistry (IHC)
Hall Bile StainSpecial stain. Immunohistochemistry (IHC)
HBME1HBME1 is an anti-mesothelial monoclonal antibody that recognizes an unknown antigen on the microvilli of mesothelioma cells. It stains normal mesothelial cells as well as epithelial mesotheliomas in a thick membrane pattern. This antibody also reacts with some carcinomas showing cytoplasmic immunostaining. Immunohistochemistry (IHC)
HCG-Beta (Human Chorionic Gonadotropin Beta)HCG-beta is secreted in large quantities by the placenta and normally is found in maternal circulation during early fetal development. Polyclonal Rabbit Anti-Human Chorionic Gonadotropin is intended for use in immunocytochemistry. The antibody labels hCG-containing cells and may be used for the demonstration of trophoblastic elements, e.g. in germ cell tumors. Immunohistochemistry (IHC)
Hemoglobin AHemoglobin A antibody reacts with the alpha chain of adult hemoglobin A. This antibody is useful in the detection of red blood cell precursors. Immunohistochemical localization of hemoglobin is excellent as an erythroid marker for the detection of immature, dysplastic, and megaloblastic erythroid cells in myeloproliferative disorders, such as erythroleukemia. In contrast, myeloid cells, lymphoid cells, plasma cells, histiocytes, and megakaryocytes stain negative with anti-hemoglobin A. Anti-hemoglobin A, combined with antibodies against CD34, CD117, CD68, and MPO can be helpful in distinguishing between reactive extramedullary hematopoiesis and that seen in neoplastic myeloid disorders in spleen. Anti-hemoglobin A is limited to expression by erythroid precursors in bone marrow and is therefore of assistance in calculating percentages of erythroid precursors. Immunohistochemistry (IHC)
Hepatitis B Core AntigenHepatitis B virus belongs to the hepatovirus family and causes type B hepatitis. Hepatitis B virus is spherical in shape with a diameter of 42 nm. Core antigens are localized within the nuclei, whereas the surface antigens are present in the cytoplasm of the infected cells. Antibodies to surface antigens appear in circulation at an early stage of infection, whereas the antibodies to the core antigens are detected in blood after several weeks. Hepatitis B core antibody targets Hepatitis B Virus Core Antigen in IHC applications. Immunohistochemistry (IHC)
Hepatitis B Surface AntigenHepatitis B virus, belongs to the hepatovirus family, and causes type B hepatitis. It is spherical in shape with a diameter of 42 nm. It contains a 27 nm partially double stranded DNA core enclosed within a lipoprotein coat. The antigens in the outer surface are called hepatitis B virus surface antigens. Antibodies to surface antigens appear in circulation at an early stage of infection, whereas the antibodies to the core antigens are detected in blood after several weeks. Hepatitis B surface antibody targets Hepatitis B Virus Surface Antigen in IHC applications. Immunohistochemistry (IHC)
HepPar1Anti-Hepatocyte Specific Antigen (HepPar1) recognizes both benign and malignant liver derived tumors such as hepatoblastoma, hepatocellular carcinoma and hepatic adenoma. It recognizes both adult and fetal liver tissue. The typical pattern is a granular cytoplasmic staining. This antibody is useful in differentiating hepatocellular carcinomas from adenocarcinomas, either primary or metastatic. HepPar1 also can be used in differential diagnostic separation of hepatoblastoma versus other small round cell tumors. HepPar1 is also expressed in a subset of gastric carcinoma. Immunohistochemistry (IHC)
HER2 Breast

This test uses the Ventana PATHWAY anti-HER-2/neu antibody (clone 4B5) for the semi-quantitative detection of HER-2 antigen in sections of FFPE normal and neoplastic tissue. The test is FDA-approved with the indication as an aid in the assessment of breast cancer patients for whom Herceptin treatment is considered. Staining is performed according to the package insert. Scoring for breast cases is performed according to ASCO/CAP 2013 guidelines. Scoring for gastroesophageal and other tissues is according to the 2010 ToGA trial standards.
HER2 is an oncogene that is over-expressed in a variety of cancers including some breast carcinomas. The expected breast cancer overexpression rate varies based on the grade and type of cancer. Known artifacts, such as edge artifact, tissue retraction and tissue crush may give the false impression of overexpression. Care should be taken to avoid assessing these areas, especially in needle core biopsies that generally harbor all of these artifacts.

Immunohistochemistry (IHC)
HGALHGAL is specifically expressed in the cytoplasm of germinal center B-cells, but is absent in mantle and marginal zone. This antibody is highly specific for germinal center B-cells and it is an ideal marker for the detection of germinal center-derived B-cell lymphomas. Immunohistochemistry (IHC)
HHV8Human Herpes Virus (HHV) 8 is the likely etiological agent of Kaposi’s sarcoma (KS), and is present in all cases. HHV 8 encodes a latent nuclear antigen (LANA) that is the product of the viral gene of 73. HHV8 has also been identified in multicentric Castleman disease (MCD), and primary effusion lymphoma (PEL). Immunohistochemistry (IHC)
HLADRThis antibody to the human leukocyte antigen (HLA) MHC class II surface antigen stains a variety of cells expressing the HLADR antigen including B-lymphocytes, macrophages and dendritic cells. HLADR antibody is useful in the differentiation of lymphomas and leukemias and it discriminates most B-cell derived lymphomas from those of T-cell origin. Immunohistochemistry (IHC)
HMB45Antibody clone HMB45 recognizes a melanoma-specific antigen by reacting with melanoma cells, nevus cells and neonatal melanocytes. HMB45 is expressed on the majority of malignant melanoma cases as well as on tumors of melanocytic differentiation. Immunohistochemistry (IHC)
HPLHuman Placental Lactogen (HPL) is a polypeptide hormone synthesized in syncytiotrophoblastic cells of placenta and has been used as a tissue marker for certain trophoblastic tumors. Immunohistochemistry (IHC)

This antibody cocktail reacts with Herpes Simplex Virus (HSV) type 1- or type 2-specific antigens and with antigens common to both types. The antibodies react with all the major glycoproteins present in the viral envelope and at least one core protein as determined by crossed immunoelectrophoresis. Neither antibody cross-reacts with cytomegalovirus or Epstein-Barr virus. The cocktail is well suited for the detection of HSV in human cellular material obtained from superficial lesions or biopsies and for the early identification of HSV in infected tissue cultures.

Immunohistochemistry (IHC)
ICOSICOS (Inducible Co-Stimulator, CD278) is a member of the CD28 family that regulates T-cell activity and immune responses. ICOS is primarily expressed on activated CD4+ and CD8+ T-cells. It plays an important role in the diagnosis of T-cell lymphomas of follicular helper T-cell origin, and is useful when combined with multiple markers for follicular helper T-cells. Immunohistochemistry (IHC)

IDH1 mutations are frequent genetic alterations in low-grade diffuse gliomas and secondary glioblastoma (70%). This alteration is observed in fewer than 10% of primary GBM cases. IDH1 IHC antibody is a diagnostic tool in assessing the IDH1 R132H mutational status and differentiating primary GBM tumors from the others.

Immunohistochemistry (IHC)
IgAIgA antibody reacts with immunoglobulin Ig alpha chains. It is useful in identifying leukemias, plasmacytomas and B-cell lineage lymphomas. Immunohistochemistry (IHC)
IgDIgD antibody reacts with immunoglobulin Ig delta chains. This antibody is useful when identifying leukemias, plasmacytomas and B-cell lineage lymphomas (in particular marginal zone lymphoma). Cytoplasmic staining is easily identified on paraffin tissue. IgD staining is also seen in normal mantle zone B-lymphocytes. Immunohistochemistry (IHC)
IgGIgG antibody reacts with immunoglobulin Ig gamma chains. This antibody may be useful in identifying plasma cytomas and B-cell lineage lymphomas, and in conjunction with IgG4 staining to assess for IgG4 associated disease. Immunohistochemistry (IHC)
IgG4 (Immunoglobulin G4)Autoimmune pancreatitis typically produces an enlarged pancreas with narrowing of the pancreatic duct, and can mimic carcinoma. It was shown that the pancreatic tissue from patients with autoimmune pancreatitis often shows moderate or marked infiltration by IgG4-positive plasma. IgG4 staining in patients with chronic alcoholic pancreatitis and pancreatic ductal adenocarcinoma was rarely observed. IgG4-positive plasma cells are a useful marker for the tissue diagnosis of autoimmune pancreatitis. Elevated IgG4+to IgG+plasma cell ratio (IgG4/IgG ratio) is helpful in distinguishing IgG4-related from non IgG4-related inflammatory conditions. Immunohistochemistry (IHC)

IgM antibody reacts with immunoglobulin Ig mu chains. This antibody is useful when identifying leukemias, plasmacytomas and B-cell lineage lymphomas.

Immunohistochemistry (IHC)
InhibinAnti-Inhibin alpha is an antibody against a peptide hormone which has a demonstrated utility in differentiating between adrenocortical tumors and renal cell carcinoma. This antibody stains most adrenal tumors but no cases of renal cell carcinomas (RCC). Sex cord stromal tumors of the ovary, as well as trophoblastic tumors, also demonstrate cytoplasmic positivity with this antibody. Immunohistochemistry (IHC)

Lack of nuclear expression of INI1 is characteristic of malignant rhabdoid tumors and epithelioid sarcomas.

Immunohistochemistry (IHC)

INSM1 is a transcription factor that is a sensitive and specific marker for neuroendocrine tumors.  It is a nuclear stain, and is as good if not better than synaptophysin and is superior to chromogranin. It is rarely expressed on adenocarcinoma or squamous cell carcinomas without neuroendocrine differentiation. 

Immunohistochemistry (IHC)
InsulinInsulin is composed of a and b chains connected through the C-peptide. The main storage site for insulin is the pancreatic islets. Antibodies to insulin are important as a marker of islet cell tumor of pancreas (insulinoma). Immunohistochemistry (IHC)
IronSpecial stain. This iron stain is used to detect and identify ferric (Fe3+) iron in tissue preparations, blood smears, or bone marrow smears. Minute amounts of ferric acid are commonly found in bone marrow and in the spleen. Abnormal amounts of iron can indicate hemochromatosis and hemosiderosis. Lack of iron identification can indicate iron-deficient anemia. Immunohistochemistry (IHC)
KappaAntibody to the kappa light chain of immunoglobulin is reportedly useful in the identification of leukemias, plasmacytomas and certain non-Hodgkin lymphomas. Demonstration of monotypism in lymphoid infiltrates is a surrogate for clonality, and therefore malignancy. Immunohistochemistry (IHC)

Ki67 is a nuclear protein that is expressed in proliferating cells. Ki67 is preferentially expressed during late G1, S, M, and G2 phases of the cell cycle, while cells in the G0 (quiescent) phase are negative for this protein. Increased proliferative activity is associated with more aggressive tumor and decreased disease-free survival period.
Note: Computer-assisted image analysis for Ki-67 is only validated for breast cancer and neuroendocrine carcinoma.

Immunohistochemistry (IHC)
Lambda (Lambda Light Chain IgG) by IHCAntibody to the lambda light chain of immunoglobulin is reportedly useful in the identification of leukemias, plasmacytomas and certain non-Hodgkin lymphomas. Demonstration of monotypism in lymphoid infiltrates is a surrogate for clonality, and therefore malignancy. Immunohistochemistry (IHC)
LangerinLangerin is a highly selective marker for Langerhans cells and the lesional cells of Langerhans cell histiocytosis. Langerin protein expression has utility in differentiating Langerhans cell histiocytosis from other non-Langerhans cell histiocytic proliferations. Immunohistochemistry (IHC)
LEF1LEF1 overexpression is highly associated with CLL/SLL among small B-cell lymphomas and may serve as a useful marker for diagnosis and differential diagnosis of the disease. Immunohistochemistry (IHC)
LHLuteinizing Hormone (LH) is a tropic hormone that modulates the secretory activity of other endocrine glands. It is produced in the anterior hypophysis of the pituitary gland. LH antibody is useful for the labeling of normal gonadotropic cells of the pituitary and also for the classification of pituitary adenomas, as well as in the differential diagnosis of primary and metastatic tumors of the pituitary. Immunohistochemistry (IHC)
LMO2LMO2 protein is expressed in normal human germinal-center (GC) and GC-derived lymphomas. In addition, it is also expressed at high levels in endothelial cells, spleen, hematopoietic precursors, and a significant proportion of acute lymphoblastic and myeloid leukemias. In diffuse large B-cell lymphoma (DLBCL), LMO2 protein expression is aligned with GC markers HGAL, CD10 and BCL6, indicating a potential role for LMO2 in the prognostic stratification of DLBCL patients. It is rarely expressed in mature T, natural killer (NK) and plasma cell neoplasms and is absent from non-hematolymphoid tissues, except for endothelial cells. Immunohistochemistry (IHC)
LysozymeLysozyme is synthesized predominantly in reactive histiocytes rather than in resting, unstimulated phagocytes. This antibody labels myeloid cells, histiocytes, granulocytes, macrophages and monocytes. It is helpful in the identification of myeloid or monocytic nature of acute leukemia. Immunohistochemistry (IHC)

MAL is a distinct molecular marker of primary mediastinal large B-cell lymphoma subtype among diffuse large B-cell lymphomas.

Immunohistochemistry (IHC)
MammaglobinMammaglobin is a breast-associated glycoprotein. In normal breast tissue, this antibody labels breast ductal and lobular epithelial cells. In tumor cells, they are reactive with all types of breast adenocarcinoma regardless of tumor differentiation and type. Adenocarcinomas from other organs rarely express mammaglobin. Mammaglobin can help in the identification of primary sites of carcinomas. Immunohistochemistry (IHC)
Masson TrichromeSpecial stain. Immunohistochemistry (IHC)
MDM2 by IHC Immunohistochemistry (IHC)
Melan A (Mart1)Melan A (Mart1, Melanoma Antigen Recognized by T-cells 1), is a differentiation antigen that is expressed in melanocytes, most melanomas. Melan A recognizes a subcellular fraction found in melanosomes. Melan A is a useful addition to melanoma panels since it is specific for melanocytic lesions. Both HMB 45 and Melan A are co-expressed in the majority of melanomas, as well as uniquely expressed in certain cases. Melan A antibody, A103 clone labels the tumor cells of a subset of adrenocortical carcinomas and sex cord tumors of the gonads. Immunohistochemistry (IHC)
MesothelinMesothelin is a 40kDa cell surface glycoprotein selectively expressed by mesothelial cells and malignant mesotheliomas, as well as by non-mucinous ovarian carcinomas, breast carcinomas, pancreatic carcinomas, and squamous tumors of the esophagus and cervix. Immunohistochemistry (IHC)
MITFMITF (microphthalmia transcription factor) is a transcription factor that regulates the development and survival of melanocytes. MITF is restricted to the melanocyte cell lineage. Anti-MITF recognizes a nuclear protein that is expressed in the majority of primary and metastatic epithelioid malignant melanomas as well as in normal melanocytes, benign nevi and dysplastic nevi. Immunohistochemistry (IHC)
MLH1MLH1, a mismatch repair protein involved in maintaining the integrity of genetic information, alongside MSH2, MSH6 and PMS2. During DNA replication, strand misalignment can occur resulting in alterations to microsatellite repeats, often referred to as microsatellite instability (MSI). These defects in DNA repair pathways have been linked to human carcinogenesis. Mutations in the MLH1 gene have been reported to be found in tumors with MSI, such as some forms of colon cancer eg. Hereditary nonpolyposis colon cancer (HNPCC), a subset of sporadic carcinomas and breast cancer. Loss of expression of MLH1 has also been reported in acute lymphoblastic leukemia, endometrial carcinoma, gastric carcinoma and ovarian carcinoma. Immunohistochemistry (IHC)
MMR Panel by IHC (MLH1, MSH2, MSH6, PMS2)

A well-defined subtype of colorectal cancer (CRC) is characterized by deficiencies in the mismatch repair (MMR) pathway. MMR status may impact prognosis and benefit of adjuvant chemotherapy. MLH1, MSH2, MSH6, and PMS2 protein expression (as assessed by IHC) and microsatellite instability analysis (MSI) assessed by PCR are well-established tools to screen for Lynch syndrome (LS), and such testing is recommended for all new colorectal cancer diagnoses. MMR IHC and molecular MSI testing also serve as companion diagnostic tests in a wide range of solid tumors for selection of certain immuno-oncology therapies.

Immunohistochemistry (IHC)
MOC31Monoclonal antibody MOC31 recognizes a membrane glycoprotein of 40kDa present on epithelial cells but not on mesothelial cells. MOC31 reacts with most adenocarcinomas of various origins, typically with strong staining pattern. Only rare cases of mesotheliomas show focal or weak staining. MOC31 antibody does not label liver as well as hepatocellular carcinoma, therefore, it will be helpful in the differential diagnosis of liver metastases versus hepatocellular carcinomas. Immunohistochemistry (IHC)
MPOMyeloperoxidase (MPO) is an important enzyme used by granulocytes during phagocytic lysis of engulfed foreign particles. In normal tissues and in a variety of myeloproliferative disorders, myeloid cells of both neutrophilic and eosinophilic types, at all stages of maturation, exhibit strong cytoplasmic reactivity for MPO. MPO is useful in differentiating between myeloid and lymphoid leukemias. Immunohistochemistry (IHC)
MPO Cytochemical

Cytochemical stain. Myeloperoxidase (MPO) is present in granules of myeloid and monocytic cells, but absent from lymphocytes. Therefore MPO is an important marker for discriminating myeloid vs. lymphoid blasts. Staining is used to distinguish acute myeloid leukemia (AML) and other myeloid leukemias from lymphoid disorders.

Immunohistochemistry (IHC)
MSAMuscle Specific Actin (MSA) antibody recognizes the alpha and gamma isotypes of skeletal, cardiac, and smooth muscle cells. It is non-reactive with other mesenchymal cells and all epithelial cells except for myoepithelium. This antibody is useful in the identification of tumors with muscle differentiation and detection of myoepithelial cells. Immunohistochemistry (IHC)
MSH2Human mismatch repair protein 2 (MSH2) is involved in the initial recognition of mismatched nucleotides during the post replication mismatch repair process. Loss of MSH2 function leads to the accumulation of replication errors, which in turn may be responsible for the multiple mutations required for multistage carcinogenesis. Mutations in MSH2 gene is linked to hereditary nonpolyposis colon cancer and to sporadic cancers which exhibit microsatellite instability. Immunohistochemistry (IHC)
MSH6Mismatch repair (MMR) genes results in failure to repair errors in repetitive sequences that occur during DNA replication. The defects in DNA repair pathways have been related to tumor carcinogenesis. MSH6 mutations appear to be associated with atypical HNPCC and in particular with development of endometrial carcinoma or atypical endometrial hyperplasia, the presumed precursor of endometrial cancer. Defects in MSH6 are also found in familial colorectal cancers (suspected or incomplete HNPCC). Immunohistochemistry (IHC)

Mucin 1 (MUC1) is a high molecular weight glycoprotein that is found on the apical surface of many glandular epithelia, including the gastrointestinal, respiratory, urinary, reproductive tracts and some hematopoietic cell lineages. MUC1 has been implicated in progression of numerous types of cancer, including breast, colon, lung, gastric and pancreatic cancers. MUC1 expression in tumors is greatly increased and accompanied by altered aberrant expression patterns that become more diffuse when compared to the normal apically restricted pattern.

Immunohistochemistry (IHC)
MUC2Mucin 2 (MUC2) expression is detected in human tissues such as normal colon, breast, prostate, and salivary gland, as well as in gastrointestinal, colonic, breast and prostate neoplasia. This antibody labels MUC2 in normal colon and colonic carcinomas where it produces intense perinuclear staining in goblet cells. Immunohistochemistry (IHC)
MUC4MUC4 is useful in the identification of low-grade fibromyxoid sarcoma (LGFMS) and sclerosing epithelioid fibrosarcoma. Immunohistochemistry (IHC)
MUC5Mucin 5 (MUC5) is expressed in gastric mucosa, and in gall bladder epithelium. MUC5 antibody is recommended for use as part of a panel of antibodies for the characterization of mucin expression and in differentiation of intestinal metaplasia as well as gastric and pancreaticobiliary carcinomas. Immunohistochemistry (IHC)
MUC6MUC6 is expressed mucopeptic neck cells and pyloric glands of the gastric mucosa. MUC6 antibody is recommended for use as part of a panel of antibodies in differentiation of gastric cancer. Immunohistochemistry (IHC)
MucicarmineSpecial stain. Mucicarmine staining is used to identify epithelial mucins, namely acid mucopolysaccharides. Staining is useful to distinguishing mucin negative undifferentiated squamous cell lesions from mucin positive adenocarcinomas. In addition, this product will stain the mucopolysaccharide capsule of Cryptococcus neoformans. Immunohistochemistry (IHC)
MUM1The MUM1 antibody is specific for the MUM1/IRF4 protein that is overexpressed in late plasma-cell-directed stages of B-cell differentiation. MUM1 is a powerful tool for understanding the histogenesis of B-cell lymphomas. MUM1 protein is an excellent marker for Hodgkin and Reed-Sternberg cells of classical Hodgkin lymphoma in combination with CD30. Furthermore, MUM1 seems to be a marker of prognostic value since it has been found that the expression of MUM1 is associated with the poor prognosis of patients with diffuse large B-cell lymphoma (DLBCL). Immunohistochemistry (IHC)
MyoD1Nuclear expression of myogenic differentiation 1 (MyoD1) is restricted to skeletal muscle tissue and has been demonstrated to be a sensitive marker of myogenic differentiation. The antibody strongly labels the nuclei of myoblasts in developing skeletal muscle tissue, whereas the majority of adult skeletal muscle is negative. MyoD1 immunostaining has been demonstrated in the majority of rhabdomyosarcomas of various histological subtypes. Immunohistochemistry (IHC)
MyogeninExpression of myogenin is restricted to cells of skeletal muscle origin. It is a useful marker for tumors of the muscle lineage, being strongly expressed in alveolar rhabdomyosarcomas. Immunohistochemistry (IHC)
MyoglobinMyoglobin is found in skeletal and cardiac muscle but not in smooth muscle. Because myoglobin appears relatively late in the maturational sequence of striated muscle, it is typically undetectable immunohistologically in embryonic neoplasms that show differentiation toward that tissue. Accordingly, pleomorphic “adult”-type rhabdomyosarcoma and rhabdomyoma are the soft tissue tumors in which myoglobin is identified most often. Immunohistochemistry (IHC)
Naphthyl Acetate Esterase (NAE and NAE w/NAF)

Cytochemical stain.

Immunohistochemistry (IHC)
Naphthyl Butyrate Esterase

Cytochemical stain.

Immunohistochemistry (IHC)
Napsin ANapsin A has a specific function in normal alveolar epithelium and is proposed to play a role in the proteolytic processing of surfactant precursors. Napsin A is reported to be predominantly expressed in lamellar bodies of type II pneumocytes, secondary lysosomes of alveolar macrophages, respiratory epithelium of terminal and respiratory bronchioles, plasma cells, and within a subset of lymphocytes in normal lung as well as in epithelial cells of renal tubules in normal kidney. It is weakly expressed in normal spleen. Past studies have also reported that Napsin A is expressed in most primary lung adenocarcinomas. Napsin A expression may also be seen in renal carcinoma. Immunohistochemistry (IHC)
NeuNNeuN is a sensitive and specific marker of neuronal differentiation in brain tumors. Immunohistochemistry (IHC)
NF (Neurofilament)Neurofilaments (NFs) are the intermediate filaments of neurons and their processes. NFs are expressed in tumors of neural origin or tumors displaying neuronal differentiation, such as neuroblastoma, medulloblastoma and retinoblastoma. This antibody labels neurons, neuronal processes and peripheral nerves, as well as sympathetic ganglion cells and adrenal medulla. The cell body of neurons, containing the non-phosphorylated neurofilament, is weakly stained. Immunohistochemistry (IHC)
NGFRNerve Growth Factor Receptor (NGFR), also known as P75NTR or CD271, is a neurotrophin receptor belonging to the tumor necrosis factor receptor family. NGFR is expressed mainly in Schwann cells and neurons, as well as a number of other non-neuronal cell types, and functions during central and peripheral nervous system development. It is useful in the diagnosis of brain tumors, peripheral nerve sheath sarcoma, melanoma, and breast malignancy. Immunohistochemistry (IHC)
NKX2.2Homeobox protein NKX2.2 plays a critical role in neuroendocrine/glial differentiation. The NKX2.2 gene was recently identified as a target of EWS-FLI-1, the fusion protein specific to Ewing sarcoma. NKX2.2 is a valuable marker for Ewing sarcoma with a sensitivity of 93% and a specificity of 89%, and aids in the differential diagnosis of small round cell tumors. Immunohistochemistry (IHC)
NKX3.1NKX3.1 is a protein encoded by the NKX3.1 gene located on chromosome 8. NKX3.1 protein has been found to be positive in the vast majority of primary prostatic adenocarcinomas. NKX3.1 stains nuclei in both normal and prostate cancer and along with other prostate-restricted markers, may be a valuable marker to definitively determine prostatic origin in poorly differentiated metastatic carcinomas. Immunohistochemistry (IHC)
NSE (Neuron Specific Enolase)In normal tissue, most neurons and their axonal and dendritic processes stain strongly positive for Neuron Specific Enolase (NSE), with the exception of Purkinje cells. Schwann cells, cells of the adrenal medulla, and paraganglia also contain NSE. Endocrine cells of the skin (Merkel cells), respiratory and GI tract epithelium, pituitary parathyroid, and pancreatic islets and C cells of thyroid all stain positively for NSE. NSE is expressed in ganglioneuromas, neuroblastomas, Schwannomas and malignant melanomas. It is also present in pheochromocytomas and paragangliomas. Carcinoids, medullary thyroid carcinomas, pituitary adenomas and endocrine tumors of the pancreas and GI tract all show positive immunoreactivity for NSE. NSE is found in neuroendocrine carcinoma of the skin (Merkel cell tumor) and small cell carcinoma of the lung. Immunohistochemistry (IHC)

Expression of nuclear protein in testis (NUT) is generally confined to the germ cells of the testis and ovary. NUT midline carcinomas are aggressive tumors with non-diagnostic morphology that overlaps with many other poorly differentiated tumors. In these tumors, rearrangement of the NUT gene at chromosome 15q14 causes NUT protein overexpression. IHC staining with NUT antibody may serve as a diagnostic alternative to FISH or molecular confirmation of 15q14 rearrangement. 

Immunohistochemistry (IHC)
OCT2Octamer Binding Transcription Factor 2 (OCT2) is present in all B-cells expressing Ig. The combination of BOB1 and OCT2 stains is helpful in distinguishing between classical Hodgkin lymphoma (at least one marker negative) and nodular lymphocyte predominant Hodgkin lymphoma (both markers expressed). Classical Hodgkin lymphoma stains as BOB1-OCT2+ or BOB1+ OCT2-, while nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) or diffuse large B-cell lymphoma (DLBCL) stains BOB1+ OCT2+. Immunohistochemistry (IHC)
OCT4Octamer Binding Transcription Factor 4 (OCT4, also known as OCT3/4, POU51) is a transcription factor and is expressed by early embryonic cells, germ cells, and stem cells. OCT4 is a nuclear marker of classical seminoma and embryonal carcinoma. It has excellent sensitivity and specificity for these two tumors, and can be used as the "screen" for these neoplasms when dealing with a metastatic tumor of unknown origin. Immunohistochemistry (IHC)
Olig2Olig2, a transcription factor, is involved in oligodendroglial specification. Olig2 expression has been reported in most glial tumors, such as oligodendrogliomas and astrocytomas. Olig2 is negative in the non-glial tumors including neuroepithelial tumors, ependymomas, subependymomas,medulloblastomas, and nonneuroepithelial tumors, such as CNS lymphomas, meningiomas, schwannomas, atypical teratoid/rhabdoid tumor, and haemangioblastomas. Immunohistochemistry (IHC)
p120 CateninP120 Catenin is a tyrosine kinase which binds to E-cadherin within the cell membrane. It is detectable in the cell membranes of a wide variety of cells, but predominates in virtually all types of epithelia. When E-cadherin is absent, P120ctn moves to the cell cytoplasm. P120ctn can be useful in the diagnostic distinction between lobular (cytoplasmic staining pattern) and ductal (membranous) breast neoplasia. Immunohistochemistry (IHC)
p16p16 (p16 -INK4a, p16-MTS1, inhibitor of CDK4) is the product of the CDKN2 gene. It inhibits the progression of the cell cycle through the G1 phase. p16 is a candidate tumor suppressor, whose gene is frequently deleted or mutated in tumors such as melanomas, gliomas, esophageal, pancreatic, lung, and urinary bladder carcinomas, and some types of leukemias. p16 expression is associated with high-risk human papillomavirus in cervical cancer and head and neck tumors. Immunohistochemistry (IHC)
p21p21 is a cyclin dependent protein kinase inhibitor and is a member of a family of proteins that functions to slow down cell division. p21 is found in t cells as they transitions from G1 phase to S phase. Low nuclear expression of p21 has been associated with poor prognosis in colon and prostate carcinomas. Immunohistochemistry (IHC)
p27p27 (KIP1) belongs to the family of cell cycle regulators that cause cell cycle arrest in G1 phase. p27 promotes apoptosis, plays a role in terminal differentiation of some tissues and mediates chemosensitivity in solid tumors. Decreased p27 KIP1 expression in tumors is associated with a more aggressive tumor phenotype such as poor histologic grade, presence of lymphovascular invasion and higher growth fraction. These findings have been validated on various cancers such as breast, colon, esophagus, stomach, lung and prostate. Immunohistochemistry (IHC)
p40p40 antibody recognizes ΔNp63—a p63 isoform. It is equivalent to p63 in sensitivity for squamous cell carcinoma, but it is markedly superior to p63 in specificity, which eliminates a potential pitfall of misinterpreting a p63-positive adenocarcinoma as squamous cell carcinoma. These findings strongly support the routine use of p40 for the diagnosis of pulmonary squamous cell carcinoma. Immunohistochemistry (IHC)

P501S protein, also called the prostein, is a type IIIa plasma membrane protein which is exclusively expressed in cells of normal and malignant prostate. P501S expression has not been detected in other normal or malignant glandular tissues.

Immunohistochemistry (IHC)
P504SExpression of P504S protein, or Alpha-methylacyl-CoA Racemase (AMACR), is found in prostatic adenocarcinoma but not in benign prostatic tissue. It has also been found to stain premalignant lesions of the prostate, high-grade prostatic intraepithelial neoplasia (PIN) and atypical adenomatous hyperplasia. P504S stains the vast majority of prostate cancers, and P504S has been shown to stain numerous other tumor types, such as hepatoma, breast carcinoma, pancreatic islet tumor and desmoplastic small round cell tumor. Immunohistochemistry (IHC)
p53The product of the p53 gene is a nuclear phosphoprotein that regulates cell proliferation. Excess accumulation of the mutant p53 gene product results in inactivation of its tumor suppressor function and cellular transformation. Overexpression of mutant p53 gene has also been associated with high proliferative rates and poor prognosis in breast, colon, lung, and brain cancer, as well as in some leukemias and lymphomas. Immunohistochemistry (IHC)
p57p57 (Kip 2, CDKN 1C) is an inhibitor of several G1 cyclin complexes and is a negative regulator of cell proliferation. The gene encoding human p57 is located on chromosome 11p15.5, a region implicated in both sporadic cancers, Wilm's tumor, and Beckwith Wiedemann syndrome (BWS, a cancer syndrome) making it a tumor suppressor candidate. p57 is useful in differentiating between complete hydatidiform mole (no nuclear p57 expression) and partial hydatidiform mole or spontaneous abortion (normal expression). Immunohistochemistry (IHC)
p63p63 is a homologue of the p53 gene and is necessary for normal breast and prostate development. Unlike other markers of myoepithelial cells and basal cells, p63 immunoreactivity is localized to the nucleus of the cells, which can offer distinct advantages over cytoplasmic labeling in certain types of cases. p63, as a marker of myoepithelial and basal cells, is extremely useful in diagnostic surgical pathology, particularly when examining difficult breast biopsies and prostate biopsies. p63 is also a marker of squamous cell and erothelial carcinomas. Immunohistochemistry (IHC)
pAKT (Phosphorylated AKT)AKT is a signal transduction protein that plays a central role in inhibiting apoptosis in a variety of tumor types. Constitutive activation of AKT (phosphorylated) has been observed in several human cancers, including lung, breast and prostate. pAKT is associated with poor prognosis as well as chemotherapy and radiotherapy resistance. Immunohistochemistry (IHC)
Pan Melanoma (S100 + Melan A + Tyrosinase)The Pan Melanoma staining combination increases sensitivity for melanomas. Since many skin biopsies are small, the triple stain conserves valuable tissue while saving time. Melan A (brown cytoplasmic) is a useful addition to melanoma panels as it is specific for melanocytic lesions. Tyrosinase (brown cytoplasmic) is a key enzyme involved in the initial stages of melanin biosynthesis. Tyrosinase is a more sensitive marker when compared to HMB45 and MART-1. It also labels a higher percentage of desmoplastic melanomas than HMB45. S100 stains Schwannomas, ependymomas, astrogliomas, almost all benign and malignant melanomas and their metastases. S100 (nuclear red) protein is also expressed in antigen presenting cells, such as the Langerhans cells in skin and interdigitating reticulum cells in the paracortex of lymph nodes. Immunohistochemistry (IHC)
Pan Melanoma/Ki67Pan Melanoma/Ki67 serves as a tool to identify the proliferation rate of melanocytic lesions. A high Ki67 rate of a melanocytic lesion raises the possibility of malignancy. Immunohistochemistry (IHC)
Pan-CytokeratinMonoclonal antibodies AE1 and AE3 recognize the acidic and basic subfamilies of cytokeratin, respectively, thus the combination of these two antibodies can be used to detect almost all human epithelia. In surgical pathology, it is an important marker for carcinoma as well as some special tumor types which have an epithelial component or differentiation. This cocktail has been used to differentiate epithelial from non-epithelial tumors. Immunohistochemistry (IHC)

Pan-TRK (clone EPR17341) is directed against the C-terminal region of TRK (tropomyosin receptor kinase) A, B, and C proteins, which are encoded by NTRK1, NTRK2, and NTRK3 genes respectively.  Pan-TRK IHC staining is a useful screen for identification of NTRK protein overexpression caused by gene fusions. Correlation of IHC staining with molecular detection of TRK fusions is moderate; discrepant cases have been described.  IHC screening is not recommended in neuroendocrine tumors, GISTs, gliomas, or adult sarcomas, as these tissues show positive staining in the absence of an NTRK translocation. Published sensitivity rates of IHC staining for detection of NTRK fusions (detected by molecular testing) are 95% and above. Follow-up molecular testing is available to confirm positivity and identify the specific NTRK gene rearranged and its fusion partner gene. 

Immunohistochemistry (IHC)
ParafibrominComplete absence of nuclear staining for parafibromin is diagnostic of parathyroid carcinoma or an HPT-JT-related tumor (hyperparathyroidism-jaw tumor syndrome). Immunohistochemistry (IHC)
ParvovirusThis monoclonal antibody clone, R92F6, recognizes a capsid protein of human parvovirus B19. Therefore, this antibody will be useful in detection of parvovirus infected cells. Immunohistochemistry (IHC)
PAX2Paired Box 2 (PAX2) is a transcription factor that is essential for kidney development. In kidneys of normal adult, Pax2 protein expression is limited to nuclei of collecting ducts and to a lesser extent in distal tubules. PAX2 is expressed in early kidney organogenesis as well as in Wilms' tumor and renal cell carcinoma. PAX2 can be useful in the diagnosis of renal cell carcinoma. Immunohistochemistry (IHC)
PAX5Paired Box 5 (PAX5) is a B-cell specific activator protein (BSAP). In early stages of B-cell development, PAX5 influences the expression of several B-cell specific genes, such as CD19 and CD20. PAX5 is expressed primarily in pro-, pre-, and mature B-cells, but not in plasma cells. There is an excellent correlation between CD20 and PAX5 expression; however, anti-PAX5 exceeds the specificity and sensitivity of L26 (CD20) because of its earlier expression in B-cell differentiation and its ability to detect all committed B-cells, including classic Hodgkin lymphoma. It is very specific to B-cell lineage and does not stain T-cells. Immunohistochemistry (IHC)
PAX8The PAX8 gene is a member of the paired box (PAX) family of transcription factors. This family plays critical roles during fetal development and cancer growth. PAX8 is involved in kidney cell differentiation, and thyroid development. PAX8 has been shown to be expressed in three of the most common types of renal cell carcinoma including clear cell, chromophobe and papillary carcinoma. PAX8 stains nuclei exclusively and performs well in formalin-fixed paraffin-embedded (FFPE) tissues. PAX8 has been shown to be positive in thyroid and ovarian carcinomas. Immunohistochemistry (IHC)
PD-L1 22C3 FDA (KEYTRUDA®) for Cervical

PD-L1 IHC 22C3 pharmDx is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) cervical squamous cell carcinoma tissue using EnVision FLEX visualization system on Autostainer Link 48.

PD-L1 IHC 22C3 pharmDx is indicated as an aid in identifying patients with recurrent or metastatic cervical cancer for treatment with KEYTRUDA® (pembrolizumab).

For gastric or GEJ cancer, please order PD-L1 22C3 FDA (KEYTRUDA®) for Gastric/GEA. For urothelial (bladder) carcinoma, please order PD-L1 22C3 FDA (KEYTRUDA®) for Urothelial Carcinoma. For non-small cell lung carcinoma (NSCLC), please order PD-L1 22C3 FDA (KEYTRUDA®) for NSCLC.

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)
PD-L1 22C3 FDA (KEYTRUDA®) for ESCC (Esophageal Squamous Cell Carcinoma)

PD-L1 IHC 22C3 pharmDx is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) esophageal squamous cell carcinoma (ESCC) and certain other tissues using EnVision FLEX visualization system on Autostainer Link 48. PD-L1 IHC 22C3 pharmDx is indicated as an aid in identifying ESCC patients for treatment with KEYTRUDA® (pembrolizumab). KEYTRUDA® is approved for use in some ESCC patients whose tumors express PD-L1 with Combined Positive Score (CPS) ≥ 10.  
For other tumor types with approved indications for this test, please search our Test Menu for "22C3" to see available options.

Immunohistochemistry (IHC)
PD-L1 22C3 FDA (KEYTRUDA®) for Gastric/GEA

PD-L1 IHC 22C3 pharmDx is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) gastric or gastroesophageal junction adenocarcinoma (GEJ, GEA) tissue using EnVision FLEX visualization system on Autostainer Link 48. PD-L1 IHC 22C3 pharmDx is indicated as an aid in identifying patients with metastatic gastric or GEJ cancer for treatment with KEYTRUDA® (pembrolizumab).

For cervical cancer, please order PD-L1 22C3 FDA (KEYTRUDA®) for Cervical. For urothelial (bladder) carcinoma, please order PD-L1 22C3 FDA (KEYTRUDA®) for Urothelial Carcinoma. For non-small cell lung carcinoma (NSCLC), please order PD-L1 22C3 FDA (KEYTRUDA®) for NSCLC.

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)
PD-L1 22C3 FDA (KEYTRUDA®) for HNSCC (Head & Neck)

PD-L1 IHC 22C3 pharmDx is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) head and neck squamous cell carcinoma (HNSCC) and certain other tissues using EnVision FLEX visualization system on Autostainer Link 48. PD-L1 IHC 22C3 pharmDx is indicated as an aid in identifying HNSCC patients for treatment with KEYTRUDA® (pembrolizumab). KEYTRUDA® is approved for use in some HNSCC patients whose tumors express PD-L1 with Combined Positive Score (CPS) ≥ 1.

For other tumor types with approved indications for this test, please search our Test Menu for "22C3" to see available options. 

Immunohistochemistry (IHC)

PD-L1 IHC 22C3 pharmDx is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) non-small cell lung cancer (NSCLC) tissue using EnVision FLEX visualization system on Autostainer Link 48. PD-L1 IHC 22C3 pharmDx is indicated as an aid in identifying NSCLC patients for treatment with KEYTRUDA® (pembrolizumab).

For gastric or GEJ cancer, please order PD-L1 22C3 FDA (KEYTRUDA®) for Gastric/GEA. For cervical cancer, please order PD-L1 22C3 FDA (KEYTRUDA®) for Cervical. For urothelial (bladder) carcinoma, please order PD-L1 22C3 FDA (KEYTRUDA®) for Urothelial Carcinoma

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)
PD-L1 22C3 FDA (KEYTRUDA®) for Urothelial Carcinoma

PD-L1 IHC 22C3 pharmDx is a qualitative immunohistochemical assay using Monoclonal Mouse Anti-PD-L1, Clone 22C3 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) urothelial carcinoma and certain other tissues using EnVision FLEX visualization system on Autostainer Link 48. PD-L1 IHC 22C3 pharmDx is indicated as an aid in identifying urothelial carcinoma patients for treatment with KEYTRUDA® (pembrolizumab). Keytruda® is approved for use in some urothelial carcinoma patients whose tumors express PD-L1 with Combined Positive Score (CPS) ≥ 10.

For gastric or GEJ cancer, please order PD-L1 22C3 FDA (KEYTRUDA®) for Gastric/GEA. For cervical cancer, please order PD-L1 22C3 FDA (KEYTRUDA®) for Cervical. For non-small cell lung carcinoma (NSCLC), please order PD-L1 22C3 FDA (KEYTRUDA®) for NSCLC.

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)
PD-L1 28-8 FDA (OPDIVO®)

PD-L1 IHC 28-8 pharmDx is a qualitative immunohistochemical assay using Monoclonal Rabbit Anti-PD-L1, clone 28-8 intended for use in the detection of PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) non-squamous non-small cell lung cancer (NSCLC), head and neck squamous cell carcinoma (SCCHN), and urothelial carcinoma tissues using EnVision FLEX visualization system on Autostainer Link 48. PD-L1 protein expression is defined as the percentage of tumor cells exhibiting positive membrane staining at any intensity.

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)

The VENTANA PD-L1 (SP142) Assay is a qualitative immunohistochemical assay using rabbit monoclonal anti-PD-L1 clone SP142 intended for use in the assessment of the PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) non-small cell lung cancer (NSCLC) tissue on a VENTANA BenchMark ULTRA instrument. Evaluation is based on either the proportion of tumor area occupied by PD-L1 expressing tumor-infiltrating immune cells (% IC) of any intensity or the percentage of PD-L1 expressing tumor cells (% TC) of any intensity. Primary or metastatic NSCLC tissues may be submitted. For bladder cancer, please order PD-L1 SP142 FDA (TECENTRIQ®) for Urothelial Carcinoma. For triple-negative breast cancer, please order PD-L1 SP142 FDA (TECENTRIQ®) for TNBC (Breast).

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)
PD-L1 SP142 FDA (TECENTRIQ®) for TNBC (Breast)

The VENTANA PD-L1 (SP142) Assay is a qualitative immunohistochemical assay using rabbit monoclonal anti-PD-L1 clone SP142 intended for use in the assessment of the PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) triple-negative breast carcinoma (TNBC) tissue on a VENTANA BenchMark ULTRA instrument. Evaluation is based on the proportion of tumor area occupied by PD-L1 expressing tumor-infiltrating immune cells (% IC) of any intensity. Primary or metastatic TNBC tissues may be submitted. Tissues with ≥1% IC are considered positive. For non-small cell lung cancer, please order PD-L1 SP142 FDA (TECENTRIQ®) for NSCLC.  For bladder cancer, please order PD-L1 SP142 FDA (TECENTRIQ®) for Urothelial Carcinoma.

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)
PD-L1 SP142 FDA (TECENTRIQ®) for Urothelial Carcinoma

The VENTANA PD-L1 (SP142) Assay is a qualitative immunohistochemical assay using rabbit monoclonal anti-PD-L1 clone SP142 intended for use in the assessment of the PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) urothelial carcinoma tissue on a VENTANA BenchMark ULTRA instrument. Evaluation is based on the proportion of tumor area occupied by PD-L1 expressing tumor-infiltrating immune cells (% IC) of any intensity. Primary or metastatic urothelial carcinoma (bladder cancer) Primary or metastatic NSCLC tissues may be submitted.  For non-small cell lung cancer, please order PD-L1 SP142 FDA (TECENTRIQ®) for NSCLC. For triple-negative breast cancer, please order PD-L1 SP142 FDA (TECENTRIQ®) for TNBC (Breast).

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)

The VENTANA PD-L1 (SP263) assay is an FDA-approved complementary diagnostic IHC test for PD-L1 status in patients with locally advanced or metastatic urothelial carcinoma (mUC) who are being considered for treatment with  IMFINZI™ (durvalumab). This is a qualitative immunohistochemical assay using rabbit monoclonal anti-PD-L1 clone SP263 intended for use in the assessment of the PD-L1 protein in formalin-fixed, paraffin-embedded (FFPE) urothelial carcinoma tissue stained with OptiView DAB IHC Detection Kit on a VENTANA BenchMark ULTRA instrument. PD-L1 high expression status as determined by this assay was associated with increased objective response rate (ORR) in a single arm study of durvalumab.

Stain-only (tech-only) testing is available to clients who have completed the test kit manufacturer’s online interpretation training.

Immunohistochemistry (IHC)
PD1Programmed death-1 (PD-1) is expressed on activated T-cells, B-cells, and myeloid cells. Anti-PD-1 is a marker of angioimmunoblastic lymphoma and suggests a unique cell of origin for this neoplasm. Unlike CD10 and BCL6, PD-1 is expressed by few B-cells, so anti-PD-1 may be a more specific and useful diagnostic marker in angioimmunoblastic lymphoma. In addition, PD-1 expression provides evidence that angioimmunoblastic lymphoma is a neoplasm derived from germinal center-associated T-cells. PD-1 expression in angioimmunoblastic lymphoma lends further support to this model of T-cell oncogenesis, in which specific subtypes of T-cells may undergo neoplastic transformation and result in specific distinct histologic, immunophenotypic, and clinical subtypes of T-cell neoplasia. Programmed Death 1 (PD1) is expressed on most T-cells and a small subset of B-cells in the light zone of germinal centers and is a useful marker of angioimmunoblastic lymphoma. Immunohistochemistry (IHC)
PerforinPerforin is a protein found in cytoplasmic granules of cytotoxic T-lymphocytes (CTLs). CTLs bind to cells that express foreign antigens and induce them to lyse. Perforin expression is significantly induced in CD8 positive T-cells, but to lesser extent in gamma/delta T-cells and NK cells. This antibody may be of value in the detection of perforin in CTLs in severe cases of graft versus host disease, chronic renal rejection and peripheral T-cell lymphomas. In addition, perforin antibody may also be useful for the detection of NK cell lymphomas, all of which express the perforin protein. Immunohistochemistry (IHC)
Periodic Acid Schiff (PAS) for fungus (PASF)Special stain. Immunohistochemistry (IHC)
Periodic Acid Schiff (PAS) with digestion (PASD)Special stain. Immunohistochemistry (IHC)
Periodic Acid Schiff (PAS)- HEMESpecial stain. Immunohistochemistry (IHC)
Periodic Acid Schiff (PAS)- Non HEMESpecial stain. Immunohistochemistry (IHC)

Progesterone Receptor (PR) belongs to a superfamily of nuclear hormone receptors. Estrogen Receptor (ER) induces PR expression, therefore, PR status serves as an indicator of an intact ER pathway. There are two known isoforms of PR; PRα and PRß. The current assays in clinical breast cancer measure both isoforms. PR is expressed in about 60-70% of invasive breast cancers. It is a weak prognostic factor by itself but a modest predictive factor that adds to the predictive value of ER for response to endocrine therapies, both in adjuvant and metastatic settings. The primary indication to assess PR in breast cancer is to predict response to hormonal therapies, such as tamoxifen, other selective estrogen receptor modulators (SERMs) and aromatase inhibitors.

Immunohistochemistry (IHC)
pHistone H3 (PHH3)Phosphohistone H3 (PHH3) is a marker of cells in the late G2-M phase of the cell cycle. It is not expressed in apoptotic cells which may be confused with mitotic figures on a routine H&E stained slide. PHH3 can be used as a surrogate of mitotic activity or as an independent prognostic marker in breast carcinomas. Immunohistochemistry (IHC)
PLAPNormally human Placental Alkaline Phosphatase (PLAP) is produced by syncytiotrophoblasts after the twelfth week of pregnancy. PLAP is expressed by both malignant somatic and germ cell tumors. PLAP can be useful in distinguishing seminoma and embryonal carcinomas from undifferentiated malignant tumors. Immunohistochemistry (IHC)
PMS2PMS2, also known as PMS1 protein homologue 2, is a DNA mismatch repair (MMR) protein. The PMS2 protein forms a heterodimer with the MLH1 protein which is then activated in the presence of ATP; this complex coordinates the binding of other proteins that repair DNA errors arising during cell preparation for cell division.
The loss of PMS2 expression in tumors can be helpful in identifying hMLH1 mutation carriers. PMS2 gene defects account for a small but significant proportion of colorectal cancers and for a substantial proportion of tumors with microsatellite instability.
Immunohistochemistry (IHC)
Pneumocystis Carinii ( Jiroveci)This antibody is specific to P. carinii (P. Jiroveci). It stains P. carinii distinctly. The staining pattern is visualized as homogeneous rings corresponding to individual cyst walls. In addition, free extra-cystic P. carinii (trophozoites) are stained. Immunohistochemistry (IHC)
Prealbumin (TTR)Prealbumin (Transthyretin, TTR) is a hormone-binding protein that participates in the plasma transport of both thyroxine and retinol (vitamin A). The vast majority are inherited in an autosomal dominant manner and are related to amyloid deposition, affecting predominantly peripheral nerves and/or the heart. A small portion of prealbumin mutations are apparently non-amyloidogenic. The human amyloid disorders, including familial amyloid polyneuropathy, familial amyloid cardiomyopathy and senile systemic amyloidosis, are caused by insoluble prealbumin fibrils. This antibody also stains pancreatic islet cells and carcinoids. Immunohistochemistry (IHC)
ProlactinProlactin is a growth factor secreted by the anterior pituitary that is necessary for the proliferation and differentiation of the mammary glands. Prolactin antibody is useful in the identification of prolactin in pituitary adenomas. Immunohistochemistry (IHC)
Prostate Triple StainThe combination of p63 + CK HMW + P504S (PIN-4 cocktail) can be extremely useful for diagnosing prostatic intraepithelial neoplasia (PIN) and/or prostate carcinoma, especially in difficult cases with limited tissue. P504 stains (cytoplasm red) prostate adenocarcinoma and atypical adenomatous hyperplasia. p63 (nuclear brown) and cytokeratin high molecular weight (HMW, cytoplasmic brown) stain basal cells of all normal (negative markers) and benign prostate glands. Immunohistochemistry (IHC)
PSAProstate specific antigen (PSA) is a glycoprotein with a molecular weight of 33-34kDa. It is restricted to the cytoplasm of acinar and ductal epithelia of normal, benign or malignant prostate tissue. Furthermore, PSA from prostatic cancers has been shown to be immunologically and biochemically similar to that of normal prostate tissue. The antibody reacts against primary and metastatic prostatic neoplasms, but not against tumors of non-prostatic origin. This antibody is useful for determining if an isolated metastasis is of prostatic origin. Immunohistochemistry (IHC)
PSAP/HPAPProstate specific acid phosphatase/human prostatic acid phosphatse (PSAP/HPAP) is a 100kDa glycoprotein present in high concentration in the prostate gland and its secretions. PSAP is specific to the benign or malignant epithelial cells of the prostate gland. Prostatic stroma, urethra and the basal cells stain negatively. Also, epithelial cells injured due to inflammation, infarction, etc. and areas of squamous metaplasia of the prostatic acini show loss of PSAP activity. Nearly all metastases of prostatic carcinoma, irrespective of site, demonstrate PSAP immunoreactivity. Immunohistochemistry (IHC)
PSMAProstate specific membrane antigen (PSMA) is a 750 amino acid type II membrane glycoprotein with folate hydrolase and neuropeptidase activity. PSMA is expressed in normal and malignant prostatic epithelium and in a subset of non-prostatic tissues. In prostate cancer, PSMA expression has been shown to correlate with disease progression, with the highest levels expressed in hormone-refractory and metastatic disease. PSMA expression has also been reported on the neovasculature of a variety of non-prostatic solid tumors. Immunohistochemistry (IHC)
PTENPhosphatase and tensin homolog (PTEN) is a tumor suppressor gene that is mutated in a wide range of cancers. PTEN plays a role in cell proliferation, apoptosis and migration. Reduced expression of PTEN has been reported in a variety of malignancies, including breast, prostate and endometrial cancer. In breast and prostate cancer, loss of PTEN expression has been shown to correlate positively with advanced stage disease. Recent studies have reported that PTEN may be a powerful predictor of response to Herceptin in HER2 positive breast cancer. Immunohistochemistry (IHC)
PTHParathyroid hormone (PTH) is expressed in normal parathyroid, parathyroid adenomas and primary and secondary hyperplasia of parathyroid. This antibody is useful in the differential diagnosis of autoimmune disorders involving parathyroid gland resulting in the production of anti-PTH & hypo-parathyroidism. Immunohistochemistry (IHC)
RB (Retinoblastoma Protein)Retinoblastoma (RB) is a tumor suppressor gene which functions as a negative regulator of the cell cycle by interacting with transcription factors including E2F1, PU1, ATF2, UBF, Elf1 and cAbl. RB protein may act by regulating transcription and loss of its function leads to uncontrolled cell growth. Aberrations in the RB gene have been implicated in cancers of breast, colon, prostate, kidney, nasopharynx, and leukemia. Immunohistochemistry (IHC)
RCC1In normal kidney, renal cell carcinoma (RCC1, gp200) is localized along the brush border of the proximal tubule. In other normal tissues, RCC is also localized along the luminal surfaces of breast lobules and ducts, the luminal surface of the epididymal tubular epithelium, within the cytoplasm of parathyroid parenchymal cells and focally within the colloid of thyroid follicles. Other normal tissues do not express similar or cross-reacting antigens. RCC1 is expressed by most primary and metastatic renal cell carcinomas. Immunohistochemistry (IHC)
ReticulinSpecial stain. Immunohistochemistry (IHC)
ROS1ROS1 gene rearrangements are reported in 1% to 2% of lung adenocarcinomas and are associated with a response to the multi-targeted tyrosine kinase inhibitor crizotinib. ROS1 rearrangement can be detected by using IHC for ROS1 protein as an alternate screening test. We recommend that any positive results be confirmed by ROS FISH studies. Immunohistochemistry (IHC)

RRM1 is crucial for DNA synthesis and damage repair. High levels of RRM1 are associated with G2 cell cycle arrest and increased apoptosis in vitro.

Immunohistochemistry (IHC)
S100S100 belongs to the family of calcium binding proteins. Antibody to S100 stains Schwannomas, ependymomas, astrogliomas, almost all benign melanocytic lesions, melanomas and their metastases. S100 protein is also expressed in the Langerhans cells in skin and interdigitating reticulum cells in the paracortex of lymph nodes. Immunohistochemistry (IHC)
S100pExpression of S100P, a member of the S100 family, is increased in a number of tumors, including pancreas, lung, breast, and ovary carcinomas. S100P can be seen in many pancreatic ductal carcinoma, and it displays no staining in the benign pancreatic ducts and acinar glands. Immunohistochemistry (IHC)
SALL4SALL4, a newly identified zinc-finger transcriptional factor, is required for the maintenance of embryonic stem cell pluripotency by modulating OCT4. SALL4 is a novel sensitive and highly specific marker for metastatic germ cell tumors, and is particularly useful for detecting metastatic yolk sac tumors. Immunohistochemistry (IHC)
SAT B2SATB2 stains colonic and osteogenic cells and their neoplasms. Immunohistochemistry (IHC)
SerotoninSerotonin is synthesized in serotonergic neurons in the central nervous system and enterochromaffin cells in the gastrointestinal tract and serotonin-containing carcinoid tumors. Serotonin may be a useful tool for characterization of carcinoids. Immunohistochemistry (IHC)
SF1SF1 is expressed in all steroidogenic tissues, including the adrenal cortex, testicular Sertoli cells, and Leydig cells, ovarian theca, hypothalamus, and anterior pituitary. SF1 is highly valuable marker to determine adrenocortical origin. Immunohistochemistry (IHC)
Simian Virus 40 (SV40)

Simian Virus 40 (SV40) is a polyomavirus that is found in both monkeys and humans. Like other polyomaviruses, SV40 is a DNA virus that has the potential to cause tumors. SV40 is believed to suppress the tumor-suppressing p53 in humans. A mutated p53 gene may contribute to uncontrolled cellular proliferation, leading to a tumor. The hypothesis that SV40 might cause cancer in humans has been a particularly controversial area of research. Some research has suggested that SV40 is associated with brain tumors, bone cancers, non-Hodgkin lymphoma and malignant mesothelioma. This antibody shows cross-reactivity to BK and JC virus, and some use it a surrogate to detect these viruses. 

Immunohistochemistry (IHC)
SMASmooth muscle actin antibody binds to smooth muscle cells and myoepithelial cells. It stains the muscularis propria and muscularis mucosae of the gastrointestinal tract, the uterine myometrium, medial layer of blood vessels, myoepithelial cells of salivary glands and other organs. The antibody does not stain skeletal and cardiac muscle, endothelium, connective tissue, epithelium or nerve. The antibody can be used to identify smooth muscle tumors (leiomyomas and leiomyosarcomas). Immunohistochemistry (IHC)
SMMHCSmooth Muscle Myosin, Heavy Chain (SMMS-1) is an antibody to smooth muscle myosin, heavy chain that reacts with human visceral and vascular smooth muscle cells. The antibody also reacts with human myoepithelial cells. It is very helpful in distinguishing between benign sclerosing breast lesions and infiltrating carcinomas in difficult cases since it strongly stains the myoepithelial layer in the benign lesions while it is negative in the infiltrating carcinomas. Immunohistochemistry (IHC)
SmoothelinSmoothelin is a novel cytoskeletal protein that reacts with the 59 kDa and 100 kDa proteins corresponding to Smoothelin A and B, respectively, which are exclusively found in smooth muscle cells (SMC). Cells with SMC-like characteristics, such as myofibroblasts and myoepithelial cells, as well as skeletal and cardiac muscle do not contain Smoothelin. Smoothelin is exclusively expressed in fully differentiated (contractile) smooth muscle cells and could be used as a tool to differentiate muscularis propria from muscularis mucosa. Immunohistochemistry (IHC)
SomatostatinSomatostatin is a useful marker of D-cells of pancreatic islet cells. D-cells are used to identify hyperplasia of the pancreatic islets. Most of these tumors are malignant, giving rise to somatostatinomas. Somatostatin suppresses gastric acid secretion, gallbladder contractions and pancreatic insulin secretion; therefore, the most common clinical manifestations of patients with these tumors are mild diabetes. Immunohistochemistry (IHC)
Somatostatin (Receptor Type 2)Somatostatin receptor type 2 (sstr2) is a receptor for somatostatins-14 and -28. This antibody has a great value in the assessment of sst2A status in human neuroendocrine tumors. Overexpression of somatostatin receptor 2 (Sst2r) in neuroendocrine tumors is diagnostically helpful and may have therapeutic implications. Immunohistochemistry (IHC)
SOX10SOX10 is a sensitive marker of melanoma, including conventional, spindled, and desmoplastic subtypes. It is also a useful marker in detecting both the in situ and invasive components of desmoplastic melanoma. SOX10 is diffusely expressed in schwannoma, neurofibroma, and granular cell tumor. SOX10 was not identified in any other mesenchymal and epithelial tumors except for myoepitheliomas and diffuse astrocytomas. Immunohistochemistry (IHC)
SOX11Nuclear protein expression of SOX-11 is highly associated with both cyclin D1-positive and negative mantle cell lymphoma (MCL). SOX-11 IHC is useful for identifying true cyclin D1-negative MCL and further defining pathologic features of CD5+ DLBCL. Routine use of anti-SOX-11 in cases of suspected CD5+ DLBCL might help identify additional cases of cyclin D1-negative blastoid MCL. SOX-11 can also be detected in some BL, LBL, and T-PLL, although the different morphological and phenotypic features of these malignancies allow easy recognition of the cases of cyclin D1-negative MCL. Immunohistochemistry (IHC)
SOX2SOX2 stains all embryonal carcinomas and is highly specific for squamous cell carcinoma. Immunohistochemistry (IHC)
SpirocheteSpirochete (Treponema pallidum) is the causative agent of syphilis. In the past, localization of the spirochete agent was achieved with silver stains such as Steiners and/or Warthin-Starry. Treponema pallidum can now be successfully localized with IHC techniques in FFPE tissue. The antibody consists of a rabbit purified IgG fraction and is highly specific for spirochete. Treponema palladium also cross-reacts with Borrelia burgdorferi (Lyme disease). Immunohistochemistry (IHC)
STAT6STAT6 is a highly sensitive and specific immunohistochemical marker for solitary fibrous tumor (SFT) and can be helpful to distinguish this tumor type from histologic mimics. Immunohistochemistry (IHC)
SurfactantPulmonary surfactant apoproteins play essential roles in keeping alveoli from collapsing at the end of expiration. SP-A is located mainly in type II pneumocytes and has been demonstrated in bronchiolo-alveolar carcinomas and adenocarcinomas of the lung. Mesotheliomas show no positive staining with this antibody. Surfactant can be helpful in the differential diagnosis of pulmonary adenocarcinomas and mesotheliomas. Immunohistochemistry (IHC)
SynaptophysinAntibody to synaptophysin reacts with neuroendocrine neoplasms of neural as well as epithelial types. In combination with chromogranin A and NSE antibodies, the antibody to synaptophysin is very useful in the identification of normal neuroendocrine cells and neuroendocrine neoplasms. Immunohistochemistry (IHC)
TCL1T-cell leukemia/lymphoma protein 1 (TCL1) is normally found in the nucleus and cytoplasm of lymphoid lineage cells during early embryogenesis. Chromosomal translocations may lead to overexpression of TCL1, resulting in T-cell leukemia and B-cell lymphoma. TCL1 is expressed in more differentiated B-cells, under both reactive and neoplastic conditions, from antigen committed B-cells and in germinal center B-cells. It is down-regulated in the latest stage of B-cell differentiation. The most useful application of TCL1 antibody is the discrimination of B-cell lymphomas from T-cell lymphomas, CD30+ anaplastic large cell lymphomas, multiple myeloma, and marginal zone B-cell lymphoma. Immunohistochemistry (IHC)

T Cell Receptor beta (TCRβ) is used as a phenotypic marker for TCRβ expressing T-cells. TCRβ is expressed by thymocytes and a majority of peripheral (α/β TCR-bearing) T-cells. This antibody does not cross-react with γ/Δ TCR-bearing T-cells.

Immunohistochemistry (IHC)
TdT (Terminal Deoxynucleotidyl Transferase)TdT is a highly specific marker for the diagnosis and classification of acute lymphoblastic lymphoma/leukemias. The determination of TdT expression is most valuable when it is important to differentiate histologically between lymphoblastic lymphoma and Burkitt lymphoma. Immunohistochemistry (IHC)
TFE3Overexpression of TFE3 is a sensitive and specific marker of Xp11 translocation in renal cell carcinomas. TFE3 is also expressed in alveolar soft part sarcoma the hallmark of which is a chromosomal rearrangement at 17q25 and Xp11.2 engendering an ASPSCR1–TFE3 fusion gene. Use of this antibody is an aid in the recognition of Xp11 translocation renal cell carcinoma and alveolar soft part sarcoma within the context of an antibody panel. Immunohistochemistry (IHC)
Thrombomodulin (TM)Thrombomodulin (TM) is a plasma membrane-related glycoprotein that has anticoagulant activity. TM antigen is found in several cell types, including megakaryocytes, mesangial cells, synovial cells, mesothelial cells, endothelial cells, and some squamous epithelial cells and their associated tumors. TM antibody labels most mesotheliomas with thick membranous staining pattern and about half of pulmonary adenocarcinomas, showing cytoplasmic immunostaining. Thrombomodulin is also a marker of urinary bladder epithelium. Immunohistochemistry (IHC)
Thyroglobulin (TGB)This antibody labels thyroglobulin (TGB) in follicular epithelial cells of the thyroid and colloid. Thyroglobulin antibody is useful in positive identification of thyroid carcinomas of the papillary and follicular types. Demonstration of thyroglobulin in a metastatic lesion establishes the thyroid origin of the tumor. Immunohistochemistry (IHC)
TIA1TIA1 (T-cell intracytoplasmic antigen) monoclonal antibody reacts with a 15 kDa cytoplasmic granule-associated protein, expressed in lymphocytes processing cytolytic potential. Most anaplastic large cell lymphomas react with TIA1. TIA1 also reacts with most large granular lymphocytic leukemias, hepatosplenic T-cell lymphomas, intestinal T-cell lymphomas, NK-like T-cell lymphomas, NK-cell lymphomas, nasal T/NK-cell lymphomas, subcutaneous T-cell lymphomas and pulmonary angiocentric lymphomas of T or NK phenotype. All B-cell lymphomas, Hodgkin and lymphoblastic leukemias are negative for TIA1. Immunohistochemistry (IHC)
TLE1Expression of the transducing-like receptor (TLE) genes, TLE1, TLE2, TLE3 and TLE4, correlate with immature epithelial cells that are progressing toward a terminally differentiated state. TLE1 antibody is an excellent discriminator of synovial sarcoma from other sarcomas, including histologically similar tumors such as malignant peripheral nerve sheath tumor. Immunohistochemistry (IHC)

Topoisomerase I (TOPO1)  is essential nuclear enzyme for replication and transcription during cell reproduction and DNA repair. Upregulation of TOPO1 increases with disease stage in colorectal and pancreatic cancers.

Immunohistochemistry (IHC)
ToxoplasmaToxoplasma is a crescent shaped sporozoan that lives as an intracellular parasite in various tissues of vertebrates and completes its life cycle in a single host. This antibody helps to identify the toxoplasma in FFPE tissues. Immunohistochemistry (IHC)

TRAP IHC is of use in the identification of hairy cell leukemia, but it is not a completely specific marker.

Immunohistochemistry (IHC)
TrichromeSpecial stain. Trichrome stains are frequently used to differentiate between collagen and smooth muscle in tumors and to identify increases in collagenous tissue in diseases such as cirrhosis of the liver. Immunohistochemistry (IHC)
TryptaseThis antibody labels a mast cell tryptase. It will also show reactivity to basophils, but to a lesser degree. Immunohistochemistry (IHC)
TS (Thymidylate Synthase)Antibody MAB4130 recognizes a 36 kDa protein identified as Thymidylate Synthase [TS], which is a target for the fluoropyrimidine group of antineoplastic drugs used to treat solid tumors. Expression of TS is associated with response to 5-fluorouracil (5-FU) in human breast, colorectal, gastric, head and neck carcinomas. Immunohistochemistry (IHC)
TSHThyroid Stimulating Hormone (TSH) is a pituitary hormone of 28 kDa that stimulates thyroid growth and production of thyroid hormones. This antibody labels thyrotropic cells of the pituitary and may be useful in the classification of pituitary adenomas and the differential identification of primary and metastatic tumors of the pituitary. Immunohistochemistry (IHC)

Thyroid Transcription Factory (TTF1) is found is found predominantly in lung and thyroid neoplasms.  The utility of TTF1 becomes apparent in the differential diagnosis of primary versus metastatic carcinomas, especially in the lung. This clone is sensitive and may show weak staining in non-lung tissues.

Immunohistochemistry (IHC)
TuberculosisMycobacterium tuberculosis is the most common cause of tuberculosis. Immunohistochemical demonstration of mycobacterial antigens is not only useful in establishing mycobacterial etiology, but can also be used as an alternative method to the conventional Ziehl-Neelsen method. Immunohistochemistry (IHC)
TyrosinaseTyrosinase is a copper-containing metalloglycoprotein that catalyzes several steps in the melanin pigment biosynthetic pathway. Mutations of the tyrosinase gene occur in various forms of albinism. Tyrosinase is one of the targets for cytotoxic T-cell recognition in melanoma patients. Staining of melanomas with this antibody showed tyrosinase in melanotic as well as amelanotic variants. Immunohistochemistry (IHC)
Uroplakin IIUroplakin II is a 15 kDa protein component of urothelial plaques. Uroplakin II mRNA was found in both bladder cancer tissues and peripheral blood of patients with primary and metastatic urothelial carcinoma of the bladder. Uroplakin II antibody [BC21] is a highly specific antibody that may be useful in identifying tumors of urothelial origin. Immunohistochemistry (IHC)
Uroplakin IIIUroplakins (UPs) are a family of transmembrane proteins (UPs Ia, Ib, II and III) that are specific differentiation products of urothelial cells. In non-neoplastic urothelium, UPIII is expressed in the luminal surface plasmalemma of superficial (umbrella) cells. UPIII detects half of urothelial carcinomas, whereas many non-urothelial carcinomas were UPIII-negative. Recent studies of UP gene expression in normal urothelium and bladder cancer specimens found that UP expression was absent after malignant transformation. Thus, UP expression might reflect the malignant potential of urothelial cancer cells as well as being cytodifferential markers of urothelial cells. Immunohistochemistry (IHC)
Varicella Zoster Virus (VZV)Varicella Zoster Virus (VZV), a member of the human herpes virus family, causes two distinct clinical manifestations: chickenpox and shingles. Primary VZV infection results in chickenpox (varicella), which may rarely result in complications including encephalitis or pneumonia. This antibody detects VZV in FFPE tissues. Immunohistochemistry (IHC)
Vascular Endothelial Growth Factor (VEGF)Vascular endothelial growth factor (VEGF) is a glycoprotein involved in angiogenesis that promotes tumor progression and metastasis. VEGF is a mitogen for vascular endothelial cells derived from arteries, veins and lymphatics, but it is devoid of consistent mitogenic activity for other cell types. VEGF is expressed in many human tumor cells, including adenocarcinomas, such as pancreatic, hepatocellular, renal cell carcinoma and fibrosarcoma. In normal tissues, VEGF expression has been observed in activated macrophages, keratinocytes, hepatocytes, smooth muscle cells, Leydig cells, embryonic fibroblasts and bronchial and choroids plexus epithelium, renal glomerular visceral epithelium, and mesangial cells. Immunohistochemistry (IHC)
VillinThis antibody recognizes villin, a cytoskeletal filament protein of 58 kDa found in human renal epithelial cells. Villin antibody is useful for the study of gastrointestinal cells in normal and tumor tissues. Immunohistochemistry (IHC)
VimentinVimentin is the major intermediate filament in a variety of mesenchymal cells, including endothelial cells, all fibroblastic cells, macrophages, Sertoli cells, melanocytes, lymphocytes and ovarian granulosa cells. Vimentin is found in all types of sarcomas and lymphomas. Positive staining for vimentin is seen in most cells of fibrosarcomas, liposarcomas, malignant fibrous histocytomas, angiosarcomas, chondrosarcomas and lymphomas. All melanomas and Schwannomas are strongly vimentin-positive. Immunohistochemistry (IHC)
Warthin StarrySpecial stain. Warthin Starry stain is intended to identify Helicobacter pylori in tissue samples. Immunohistochemistry (IHC)
Wright GiemsaCytochemical stain. The Wright Giemsa stain is used to stain peripheral blood and bone marrow smears for study of blood cell morphology. Immunohistochemistry (IHC)
WT1Wilms tumor susceptibility gene 1 protein (WT1) has diagnostic utility in the distinction of mesothelioma from adenocarcinoma in tissue sections of pleural tumors. WT1 diffusely stains most ovarian serous carcinomas and all Wilms tumors. Immunohistochemistry (IHC)
ZAP70A prognostic factor in CLL/SLL. Immunohistochemistry (IHC)