The noncoding RNA miR-21 is a downstream target of Smad3, which is known to activate the transcription of miR-21 in the presence of TGF-β [174]; miR-21 also inhibits pro-apoptotic signals and ameliorates glomerular injury induced by TGF-β and hyperglycemia [175]. This evidence concerns the gene TGFB1 and Hyperglycemia.