• Immunohistochemistry (IHC)
p16 (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.
Turnaround time
Global: 2 Day, Tech-Only (stain only): 1 Day

Level of Service

  • Global
  • Technical Only
New York Approved: Yes

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

Storage & Transportation: Use cold pack for transport, making sure cold pack is not in direct contact with specimen. NYS clients please provide date and time of Collection.

CPT Code(s)*

88342 x 1 or 88341 x 1

*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.

Last Updated: January 22, 2025

Get in touch

Our Client Services team is on hand to help. Please call us at 866.776.5907, Option 3.