Previous genome-scale sequencing studies have identified mutations in a number of genes involved in the initiation and progression of melanoma, including BRAF (50%), NRAS (20–30%), neurofibromin 1 (NF1) (10–15%), and cyclin-dependent kinase inhibitor 2A (CDKN2A) (20–40%) [3]. The gene discussed is CDKN2A; the disease is melanoma.