ARG1 and neoplasm: N2 TANS enhances the immunosuppressive milieu by expressing high levels of PD-L1, arginase-1 (ARG1), reactive oxygen species (ROS), nitric oxide (NO), IL-10, and TGF-β1, shaping the tumor landscape and impairing T-cell-mediated cytotoxicity (42) The expression of both CXCL8 and Arg-1 by neutrophils is correlated with ICI therapy failure and poor prognosis in NSCLC (43, 44).