The CDKN2A gene locus encodes two melanoma predisposition genes with different functions: CDKN2A/p16, a tumor suppressor that imposes control through the retinoblastoma (Rb) pathway [8, 9], and CDKN2A/ARF, another tumor suppressor that functions through the p53 pathway [10]. The gene discussed is TP53; the disease is melanoma.