TGFB1 and renal fibrosis: Among the several TGF-β isoforms, TGF-β1 notably possesses the ability to initiate renal fibrosis either by canonical (SMAD-based) or non-canonical (non-SMAD-based) signaling pathways, by activating the myofibroblasts to produce excessive extracellular matrix (ECM) production and/or inhibiting ECM degradation (Lan, 2011).