Ipilimumab (Anti-CTLA-4), Pembrolizumab, Nivolumab (Anti-PD-1), and Atezolizumab, Durvalumab, Avelumab (Anti-PD-L1) have shown significant efficacy in clinical and clinical trials, and have been approved for treating a number of cancers. Here, CTLA4 is linked to cancer.