A meta-analysis from Smith et al. identified several risk factors for the development of subsequent primary melanomas, as follows: CDKN2A mutation and high nevus count with high certainty of evidence, increasing age, presence of an atypical nevus, moderate nevus count with moderate certainty of evidence and male sex, family history of melanoma, light skin color, first lesions occurring on the head or neck, and inadequate sun protection with low certainty of evidence [12]. This evidence concerns the gene CDKN2A and melanoma.