Several anti-LAG-3 mAbs are currently undergoing clinical trials, and the combination of relatlimab (anti-LAG-3) with nivolumab (anti-PD-1) has already been approved for treating unresectable or metastatic melanoma, based on results from the Phase II/III RELATIVITY-047 (NCT03470922) [213]. This evidence concerns the gene PDCD1 and metastatic melanoma.