In melanoma, multiple ICI, including nivolumab and pembrolizumab (anti-PD1 mAb) and ipilimumab (anti-CTLA-4 mAb), are FDA-approved for unresectable or metastatic disease, either as monotherapy or in combination (nivolumab plus ipilimumab) [47]. The gene discussed is PDCD1; the disease is metastatic neoplasm.