TGFB1 and idiopathic pulmonary fibrosis: In the presence of a disrupted cellular contact and active TGF-β1, E-cadherin and the epithelial integrin α3β1 associate with TGF-β1 receptors, where Tyr654 in β-catenin gets phosphorylated by the epithelial integrin in primary alveolar epithelial cells (AECs) and the phosphorylated β-catenin forms a complex with phospho-SMAD2, resulting in EMT initiation in idiopathic pulmonary fibrosis (IPF) (161, 162).