CTLA4 and ischemic stroke: However, a large number of studies have shown that immune checkpoint inhibitors targeting programmed cell death 1 (PD1), programmed cell death ligand 1 (PDL1) and cytotoxic T-lymphocyte associated protein 4 (CTLA4) can effectively improve the prognosis of many cancer patients, but it may lead to some vascular and cardiac toxicity such as atherosclerosis, ischaemic stroke or myocardial infarction and other adverse reactions [7, 60, 61].