p16INK4a acts as a tumor suppressor through multiple biological functions, including the inhibition of cell cycle progression,1 the induction of senescence2 and differentiation,3 and its involvement in apoptosis4 and DNA repair.5 Overexpression of the p16INK4a gene induced the inhibition of cell proliferation, which has mainly been considered to result from arrest in G1 phase of the cell cycle6 as well as the lengthening of S-phase.7 The gene discussed is CDKN2A; the disease is neoplasm.