For example, Id-1 inhibits p16INK4a/RB pathway leading to the bypass of replicative senescence in primary cells (Alani et al, 2001; Ohtani et al, 2001) and induces serum-independent proliferation in human prostate cancer cells (Ouyang et al, 2002b). This evidence concerns the gene CDKN2A and prostate carcinoma.