ARG1 and neoplasm: However, the function of M2 macrophages can also be adversely affected by tumor exploitation by producing immunosuppressive and pro-angiogenic factors such as IL-10, arginase 1 (ARG1), TGF-β, or vascular endothelial growth factors (VEGFs), which stimulate tumor cell proliferation, invasion, metastasis, and angiogenesis [41].