Genome-wide association studies (GWAS) have now firmly identified twenty loci as linked to sporadic melanoma development in the general population, with genes at these loci including regulators of telomere length and function such as TERT, regulators of the cell cycle such as CDKN2A, and genes involved in pigmentation and the control of naevus count (1,2). The gene discussed is CDKN2A; the disease is melanoma.