ARG1 and neoplasm: M2 TAMs secrete anti-inflammatory cytokines, including arginase 1 (ARG1), interleukin-13 (IL-13), IL-10, IL-4, vascular endothelial growth factor (VEGF), and TGF-β to activate a Th2-type immune response and promote tumor progression by stimulating angiogenesis, maintaining tumor cell stemness, facilitating immune infiltration, remodeling tissues, and inducing drug resistance [1,10,15,16,17] (Figure 1).