CD274 and neoplasm: Under physiological situations, the polarizatioon of macrophages into the proinflammatory and antitumor M1 phenotype was made; nevertheless, tumor cells can induce macrophages to switch to activated alternatively the M2 phenotype via some pathways (CCL-2, IL-4, IL-6, IL-8, IL-10, TGF-β, and PD-1/PD-L1 [programmed cell death-ligand 1]).