CD274 and melanoma: Monoclonal antibodies against PD-1 (Pembrolizumab, Nivolumab, and Cemiplimab) or PD-L1 (Atezolizumab, Avelumab, and Durvalumab) have been approved by FDA for the treatment of a series of malignancies including breast cancer, bladder cancer, colorectal cancer, lung cancer, hepatoma, and melanoma (Massard et al., 2016;Kim, 2017; Xin Yu et al., 2020).