The impairment of the p53 pathway in melanoma has been also attributed to either the deregulation of mouse double minute 2 (MDM2), the major ubiquitin ligase involved in p53 degradation or inactivation of the cyclin-dependent kinase inhibitor 2A (CDKN2A) locus, encoding p16INK4A and p14ARF tumour suppressors [28]. This evidence concerns the gene CDKN2A and melanoma.