Alternate Test Names:
p16; E6H4

Methodology: IHC

Clinical Significance:
Identifies: p16-INK4A, a tumor suppressor gene that plays an important role in cell cycle regulation. High-risk types of human papillomavirus (HPV) have been associated with increased expression of viral oncogenes E6 and E7, both of which impact various cell cycle regulating proteins. The retinoblastoma gene product is inactivated by E7, resulting in unregulated transcription of p16. Overexpression of the p16 protein has been observed in CIN I, II & III, where it can serve as a surrogate for the presence of high risk HPV types. In the context of head and neck squamous cell carcinomas, p16 overexpression can serve as a prognostic marker.

Subcellular Localization: Nuclear and cytoplasmic

Organ: OB/GYN

Disease State:

CPT Code(s): 88342 or 88341 (reference only; CPTs may vary)

Turnaround Time: Within 1-2 business days of receipt

Schedule: Monday - Friday

Specimen Requirements:
• Formalin-fixed, paraffin-embedded (FFPE) tissue block or cell block - OR -
• 1 unstained slide for each test requested plus 3-4 additional unstained slides cut at 4µm