TGFB1 and idiopathic pulmonary fibrosis: In an experimental model of heart failure, characterized by an increased TGF-β1 expression and atrial fibrosis, the authors showed that the administration of the drug pirfenidone (a novel antifibrotic agent in use for idiopathic pulmonary fibrosis) was able to significantly reduce the expression of TGFβ1, with a concomitant decrease in atrial fibrosis, conduction abnormalities, and AF vulnerability (Lee, 2006).