CTLA4 and neoplasm: ICIs block immune checkpoints or immunosuppressive receptors, such as cytotoxic-T-lymphocyte-associated protein 4 (CTLA-4) and programmed death receptor-1 (PD-1) to improve the cytotoxicity and proliferative capacity of tumor-infiltrating lymphocytes (TILs) [26,27,28,29,30,31,32,33,34,35].