CD274 and neoplasm: Nowadays, several monoclonal antibodies have been approved for immune checkpoint blockade, such as nivolumab (Halmos et al., 2020), pembrolizumab (Halmos et al., 2020), avelumab (Verschraegen et al., 2020), etc. The monoclonal antibodies competitively bind and block PD-1 on T-cells or PD-L1 on tumor cells.