TGFB1 and renal fibrosis: HGF restricts the expression of TGF-β1 in renal fibrosis, and inhibit podocyte apoptosis and endothelial cell apoptosis through the cellular mechanism of Smad2 and Smad3 in TGF-β1, while inhibiting tubular epithelial cell apoptosis and epithelial-mesenchyme transformation, and activation of mesenchymal fibroblasts.