In 2011, the United States Food and Drug Administration (FDA) approved the anti–CTLA-4 antibody ipilimumab for patients with stage IV melanoma, followed by the anti–programmed cell death 1 (anti–PD-1) antibodies nivolumab and pembrolizumab in 2014 for the second and subsequent line treatment. The gene discussed is CTLA4; the disease is melanoma.