Melanoma, a malignancy of the pigment-producing cells of the skin, accounts for approximately 5% of all new cancer cases in the United States annually.1 Melanoma is a highly aggressive malignancy with historical 5-year survival rate of regionally advanced melanoma and metastatic melanoma estimated at 10% and 5%, respectively.1,2 The treatment of melanoma has improved significantly since the arrival of immune checkpoint inhibitor ipilimumab, an anti-CTLA-4 antibody, in 2011. This evidence concerns the gene CTLA4 and melanoma.