Induction of intrauterine growth restriction (IUGR) in rats resulted in impaired alveolar development of the rat pups, which was associated with decreased TGF-β1 expression, downregulation of the TGF-β responsive gene plasminogen activator inhibitor-1 (PAI-1) and dysregulation of the composition and remodeling of the ECM components (63). Here, TGFB1 is linked to fetal growth restriction.