Although nevi and melanomas share initiating genetic alterations such as oncogenic mutations in BRAF and NRAS, melanomas often show recurrent patterns of chromosomal aberrations such as losses of chromosomes 6q, 8p, 9p, and 10q along with gains of chromosomes 1q, 6p, 7, 8q, 17q, and 20q, while benign nevi tend to have no detectable chromosomal aberrations by comparative genomic hybridization (CGH) or karyotyping [73–75]. This evidence concerns the gene NRAS and melanoma.