Efficacy of nivolumab-relatlimab was reported in a global phase 3 trial for advanced melanoma (RELATIVITY-047), confirming superiority of this combination over nivolumab alone.6–8 In contrast nivolumab-relatlimab subsequent to disease progression on anti-PD-1-based therapy demonstrated limited activity with ORR 9–12% and median PFS 2–3 months in the RELATIVITY-020 trial.9 The impact of monotherapy with anti-LAG-3 compared to anti-PD1 or the combination on outcome has not been previously evaluated. This evidence concerns the gene PDCD1 and melanoma.