TGFB1 and pulmonary fibrosis: TGF-β1 is known to play a key role in the pathogenesis of pulmonary fibrosis by activating Smad signaling pathways (Hu et al., 2003; Stolzenburg et al., 2016), and interventions targeting TGF-β1 or Smad signaling pathways are widely believed to have potential as treatments for pulmonary fibrosis (Stolzenburg et al., 2016).