CD274 and neoplasm: However, for a transformed cell to survive, it must attain an immunosuppressive phenotype, such as downregulation of MHC class I expression and upregulation of programmed cell death receptor ligand-1 (PD-L1) and CD47, which hinder the anti-tumor immune response by engaging and suppressing the activated T cells and relaying ‘don’t eat me’ signal to the phagocytic macrophages, respectively (120, 121).