TGFB1 and neoplasm: Many studies have shown that TAMs secrete a variety of cytokines that can promote tumour cell proliferation, including epithelial growth factor (EGF), platelet-derived growth factor (PDGF), transforming growth factor-β1 (TGF-β1), hepatocyte growth factor (HGF) and basic fibroblast growth factor (bFGF) (38).