CD274 and cancer: Antibodies that target and block PD-L1 (avelumab), PD1 (pembrolizumab, nivolumab, JS001, or PDR001), or CTL4 (ipilimumab) have been used in a number of cancers with promising results, including melanoma, renal, lung, prostate, and bladder cancers, and equivalent trials are now in progress for GEP-NETs.