Mouse embryonic fibroblasts derived from CDK4R24C/R24C mice (CDK4R24C is resistant to p16INK4a inhibition) (Rane etal., 2002) and human diploid fibroblasts overexpressing CDK4 have an extended lifespan (Morris etal., 2002; Ramirez etal., 2003) and carcinogen-treated mice carrying oncogenic CDK4 are highly susceptible to melanoma development (Sotillo etal., 2001). This evidence concerns the gene CDK4 and melanoma.