M2-type macrophages then secrete epidermal growth factor receptor (EGFR), transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), IL-10, IL-6 and arginase-1, promoting tumor angiogenesis and tumor progression [54]. Here, ARG1 is linked to neoplasm.