Previous reports revealed that the incidence of excessive p21 down-regulation and cyclin-D up-regulation are frequently observed in human cancers, particularly in melanomas, cervical and prostate carcinomas, and that these abnormal expressions appear to be associated with elevated tumor spread and poor treatment outcome (Abbas and Dutta, 2009; Musgrove et al., 2011). The gene discussed is CDKN1A; the disease is melanoma.