Correlations between the CDKN2A mutation status and melanoma risk factors in North American melanoma-prone families have shown that in addition to the increased risk associated with CDKN2A mutations, the total number of nevi and the presence of dysplastic nevi were associated with a higher risk of melanoma, Sun exposure and a history of sunburn is associated with melanoma risk in melanoma-prone families. This evidence concerns the gene CDKN2A and dysplastic nevus.