ARG1 and glioblastoma: GAMs express molecules associated with M2 anti-inflammatory phenotype in mouse GBM models that include upregulation of Arginase-1 (Arg-1), IL-10, transforming growth factor-β (TGFβ), CD206, CD163, CCL17, and CCL22, and NF-κB activation associated with M2 differentiation (39, 42, 43).