SMAD7 and renal fibrosis: Wang and colleagues demonstrated that overexpression of miR-21-5p could lead to transforming growth factor beta (TGF-β) induced epithelial-mesenchymal transition (EMT) by inhibiting smad7, and that miR-21-5p may provide an alternative target to directly suppress TGF-β-mediated renal fibrosis in DKD47.