TGFB1 and renal fibrosis: Increasing evidence shows that TECs-derived profibrotic factors, including transforming growth factor-β1 (TGF-β1), connective tissue growth factor (CTGF), platelet-derived growth factor (PDGF), are a driving force in the progression of renal fibrosis due to their roles in activating surrounding fibroblast [4, 6].