p16 ink 4a. p16 (INK4a). Cyclin dependent kinase (CDK) inhibitor. Decelerates cell cycle by inactivating CDK’s that phosphorylate Rb protein. Overexpression in CIN and invasive cancer due to functional inactivation of Rb by HPV E7 protein. p16 (INK 4a) expression patterns. B. A. D. C. F.
p16 and the cervix
A:CIN 1 B:CIN 2-3
C:CIN 3 in an endocervical gland D:cGIN
E:Invasive squamous cell carcinoma F:Adenocarcinoma