TGFB1 and idiopathic pulmonary fibrosis: Similarly, MMP-7, which is highly expressed in IPF lung tissue and plasma, is secreted by damaged AECs and drives fibrosis through multiple mechanisms, including cleaving basement membrane components such as E-cadherin and integrin β4, activating bioactive molecules including osteopontin and TGF-β, and promoting fibroblast activation and collagen deposition (Richards et al., 2012).