TGFB1 and renal fibrosis: Key fibrogenic factors include TGF-β1, connective tissue growth factor (CTGF), angiotensin II, platelet-derived growth factor (PDGF) and fibroblast growth factor (FGF)2, among which, TGF-β1 has been regarded as key modulator of renal fibrosis (Bottinger, 2007), and the role of TGF-β in fibrosis has been extensively studied and well summarized (Branton and Kopp, 1999; Bottinger, 2007; Lan, 2011).