CTLA4 and cancer: Generally speaking, current efforts in cancer immunotherapy fall into three main approaches (122): 1) the blockade of immune checkpoints such as anti-PD-1/PD-L1 and anti-CTLA-4 to restore or potentiate the antitumor effect of immune cells (123); 2) adoptive cellular therapy, including the use of TIL therapy (124), engineered T-cell therapy (e.g., chimeric antigen receptor [CAR] T-cell therapy and TCR therapy (125)), CAR-NK cell therapy (126), and CAR-macrophage therapy (127); and 3) therapeutic cancer vaccines (128).