CD274 and neoplasm: Generally, cancer cells could evade anti-tumor immunity by adopting active immunogenicity reduction strategies, including reduced expression of tumor antigens, diminished MHC-I expression for reduced antigenic recognition by T cells, and aberrant expression of immune checkpoint proteins, such as programmed death ligand-1 (PD-L1), which inhibits existing host anti-tumor immunity (Kim and Seo, 2018; Looi et al., 2019; Tang et al., 2014).