Methodology
Immunohistochemistry (IHC)
Test Description
FOX 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.
Specimen Requirements
  • A formalin-fixed, paraffin-embedded (FFPE) tissue block is preferred specimen type
  • or
  • One (1) unbaked, unstained slide for H&E staining (required) and two to three (2-3) positively charged unstained slides (all cut at 4-5 microns) for each test/antibody ordered
  • Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Storage and Transportation
Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.
CPT Code(s)*
88342 x 1 or 88341 x 1
Turnaround Time
24 hours
Level of Service
Stain Only

*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.