TGFB1 and pulmonary fibrosis: TGF‐β1 is involved in the processes of pulmonary fibrosis and liver fibrosis.24, 52 A previous study demonstrated that constitutive expression of dominant‐negative TGFβRII in the posterior left atrium resulted in a significant decrease in atrial fibrosis via inhibition of the TGF signalling pathway and attenuated fibrosis‐induced changes in atrial conduction and restitution to decrease AF.27 The increased level of TGFβRII in the TGF‐β1 group showed that TGFβRII may participate in TGF‐β1‐induced fibrosis.