In a clinical trial involving 11 patients with stage III/IV metastatic melanoma, an ECOG status of 0–1, and no previous treatment, researchers evaluated the efficacy of nivolumab, an anti-PD-1 therapy, in combination with adoptive cell transfer (ACT) using TILs expanded with anti-4-1BB agonism. This evidence concerns the gene PDCD1 and metastatic melanoma.