CD274 and cancer: Studies have found that cancer cells are capable of evading clearance by macrophages through the overexpression of anti-phagocytic surface proteins, called “don’t eat me” signals, such as CD47 [9], programmed cell death ligand (PD-L1) [10] and β2-microglobulin (B2M) associated with class I major histocompatibility complex [11].