Moreover, arginine depletion in the TME promotes the accumulation of CD11b+Gr1+ MDSCs that suppress antitumor functions of T cells (123), and pharmacological inhibition of arg-1 suppresses the activity of G-MDSCs, restoring the production of IFN-γ and granzyme B by T cells and reducing tumor growth (124). The gene discussed is GZMB; the disease is neoplasm.