CTLA4 and neoplasm: The representative drugs include monoclonal antibodies against programmed cell death receptor-1 (PD-1) [1, 2], cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) [3], and lymphocyte-activation gene 3 (LAG3) [4], which inhibit T cell activity and contribute to immune evasion from the tumor.