Currently, there are 3 types of immunotherapy treatments approved for unresectable or metastatic melanoma treatment regardless of the BRAF status: 2 anti–programmed death 1 (PD-1) agents, namely nivolumab and pembrolizumab; a single anti–programmed death 1 ligand (PD-L1) agent, atezolizumab; and a single anti–cytotoxic T-lymphocyte-associated protein 4 (CTLA4) agent, ipilimumab [6,7,9]. The gene discussed is CTLA4; the disease is metastatic melanoma.