Although the therapeutic effect of chemotherapy for melanoma is limited, it can be used as an adjuvant therapy in some cases.[5,6] Immunotherapy is a new type of treatment in recent years, and many studies have revealed many biomarkers related to cancer immunotherapy,[7,8] so immune checkpoint inhibitors such as anti-PD-1 and anti-CTLA-4 antibodies have been developed. This evidence concerns the gene CTLA4 and melanoma.