As the most extensively used ICIs at present, checkpoint inhibitor-based immunotherapies that target the cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and the programmed cell death receptor 1/programmed cell death ligand 1 (PD-1/PD-L1) pathway have achieved impressive success in the treatment of different cancer types (16). The gene discussed is CTLA4; the disease is cancer.