The expression of genes that promote renal fibrosis (Smad2, Smad3, Smad4, Shh, Dll1) was downregulated, while the expression of genes that inhibit renal damage (Smurf1, Smurf2, Smad1, Smad5, Smad6, Smad7) was increased in the WT+miPEP31 group (PEP1/2) compared with the WT+ cPEP (SCR1/2) group (Fig. 3F). Here, SMAD6 is linked to renal fibrosis.