In the last decade, immune checkpoint blockades (ICBs) of targeting cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death receptor-1 (PD-1) and its associated ligand (PD-L1) as monotherapy or combination therapy, have revolutionized the treatment of metastatic melanoma [[1], [2], [3], [4]]. This evidence concerns the gene CTLA4 and metastatic melanoma.