TGFB1 and renal fibrosis: For example, transplantation of BMSCs decreased TGF-β expression and intracellular Smad2 downstream phosphorylation (TGF-β1 binding to its receptor), which in turn inhibited the number of α-SMA-positive cells [99,100,101], resulting in lower levels of myofibroblast proliferation and differentiation, reduced myofibroblast-induced ECM production and epithelial-mesenchymal transition (EMT), and ultimately inhibited the transition from tubular epithelium to myofibroblasts phenotypically, eventually altered renal fibrosis process [101].