Loss-of-function mutations of p16(INK4a) have been identified in a large number of human tumors. An established biochemical function of p16 is its ability to specifically inhibit cyclin D-dependent ki
N, normal adjacent tissue; T, tumor tissue. For RT qPCR (PCR) data: −, undetectable amounts of mRNA; +, detectable mRNA expression; +#, high amounts of mRNA. For Western (W) analysis: −, not detected;
E4F1 is a ubiquitously expressed zinc-finger protein of the Gli-Kruppel family that was first identified, more than 30 years ago, as a cellular target of the adenoviral oncoprotein E1A13S (Ad type V),