TGFB1 and idiopathic pulmonary fibrosis: For instance, although MMP-1 efficiently degrades collagen, it is predominantly expressed in AECs during IPF, where it promotes epithelial repair and inhibits apoptosis—effects suppressed by the dominant profibrotic mediator TGF-β (Sang, 1998; Richards et al., 2012; Kobayashi et al., 2014; Link et al., 2025).