Multiple ICIs targeting CTLA4 and PD-1 or PD-L1 have been approved for use in cancer therapy due to their promising long-lasting therapeutic efficacies in many types of cancer.267 In addition, ICIs targeting TIGIT,268,269 TIM-3270 and BTLA271 have also demonstrated unprecedented preclinical results and are in clinical development. This evidence concerns the gene CTLA4 and cancer.