Immune checkpoint inhibitors, such as those targeting cytotoxic T lymphocyte‐associated molecule 4 (CTLA‐4), programmed cell death receptor 1 (PDCD1, also named PD‐1), and programmed cell death ligand 1 (CD274, also named PD‐L1), have revolutionized cancer treatment.25 The gene discussed is CTLA4; the disease is cancer.