SMAD2 and renal fibrosis: Additionally, the results of this study also showed that ZYQYF could effectively inhibit the expression of TGF-β1, Smad-2, and Smad-3 proteins and mRNA, and increase the expression of Smad-7 protein and mRNA in kidney tissues, thereby regulating the TGF-β1/Smads signaling pathway-mediated renal fibrosis process, and the findings also indicated a dose-effect relationship.