TGFB1 and atrial fibrillation: In summary, our study determined that the occurrence of postoperative AF in patients who have no previous history of AF was correlated with atrial fibrosis and that the MAPKs/TGF-β1/TRAF6 signaling pathway was altered in these patients, which suggests that this pathway is an important signaling pathway in the CTGF expression induced by AngII.