TGFB1 and neoplasm: Tumour cells primarily orchestrate the recruitment and activation of stromal cells that are the major depositors of ECM components in the tumour microenvironment (Fig. 2b) by the secretion of various pro-fibrotic growth factors and inflammatory factors such as TGF-α, TGF-β, fibroblast growth factor (FGF)-2, platelet-derived growth factor (PDGF) and epidermal growth factor (EGF)21.