ARG1 and gastric cancer: ,36 Recent studies also demonstrated that MDSCs mainly exert immunosuppressive functions through the induction of Arg-1 and L-arginine depletion.37, 38, 39 Circulating MDSCs in patients with gastric cancer expressed Arg-1 that was associated with decreased CD8+ T-cell proliferation as well as with reduced IFN-γ production and granzyme B secretion from those cells.40