TGFB1 and renal fibrosis: Overexpression of Smad7 could block activation of TGF‐β/Smad signalling while reduction of renal Smad7 could result in over‐activation of TGF‐β/Smad signalling and progression of renal fibrosis.37 In this study, we found AKBA increased the expression of Smad7 in vivo and in vitro experiments.