CD274 and neoplasm: In general, circulating and disseminated tumor cells acquire a variety of immune-escape mechanisms, including alterations in the expression of major histocompatibility complex (MHC) molecules, Natural killer (NK)-cell ligands, Fas, Fas ligand (FasL), and immune-checkpoint molecules including CD47 and programmed cell death 1 ligand 1 (PD-L1) [82].