CD274 and gastric cancer: The aim of this study was to investigate the role of dextran sulfate (DS) in M0-to-M2 macrophage polarization and its effect on programmed death-ligand 1 (PD-L1) expression, invasion, migration, proliferation, and apoptosis of human gastric cancer cells (HGCCs) through its action on M2 tumor-associated macrophages (M2-TAMs).