However, checkpoint inhibitors are a class of humanized monoclonal antibodies (mAbs) such as pembrolizumab (anti-PD-1), nivolumab (anti-PD-1), and atezolizumab (anti-PD-L1) that have been developed for use as immunotherapy drugs to block specific checkpoint proteins from binding with partner proteins, and therefore enhance the immune response against cancer cells (Marhelava et al., 2019). Here, CD274 is linked to cancer.