TGFB1 and renal fibrosis: Overall, these findings strongly suggest the functional role of miR-140-5p in TGF-β1/smad-mediated renal fibrosis and indicate the upregulation of miR-140-5p reversed TGF-β1-induced HK2 cell differentiation and collagen generation, leading to the protection of HK2 cells from TGF-β1-induced renal fibrosis.