As important advances in tumor therapy in recent years, ICIs mainly take effect by inhibiting immune checkpoints through antibodies [such as PD-1, Programmed cell death 1 ligand 1 (PD-L1), CTLA-4, etc.], so as to restore and improve the ability of effector T lymphocytes and specifically recognize and kill tumor cells, enhancing the systemic anti-tumor immune response. This evidence concerns the gene CTLA4 and neoplasm.