The advent and approval of immune checkpoint blockade (ICB; e.g., anti-programmed death 1 [PD-1], anti-cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4] and anti-Lymphocyte Activation Gene 3 [LAG-3]) agents has revolutionized the treatment landscape of melanoma, bringing forth an era in which ten-year disease-specific survival in the metastatic setting surpasses 50%, compared with less than 10% previously [1]. This evidence concerns the gene LAG3 and melanoma.