The TGF-β/Smad2/3 signalling pathway regulates atrial fibrosis and AF.35,36 Consistent with this paradigm, we found that LIPUS lowers Adam19 and suppresses Smad2/3 activation, while AAV9-mediated Adam19 overexpression reactivates the pathway and abolishes LIPUS protection. This evidence concerns the gene SMAD2 and atrial fibrillation.