Inhibition of PAI-1 activity by the specific inhibitor SK-216 reduces the profibrotic effects of TGF-β, including epithelial–mesenchymal transition and fibroblast-to-myofibroblast differentiation, suggesting that PAI-1 acts as a key downstream effector in the pathogenesis of pulmonary fibrosis [92]. Here, TGFB1 is linked to pulmonary fibrosis.