Studies from this laboratory and from others have shown that PAI‐1 plays a critical role in the development of lung fibrosis, although the mechanism whereby PAI‐1 promotes lung fibrosis remains elusive (El‐Deiry et al., 1992; Dimri et al., 1995; Citrin et al., 2013; Disayabutr et al., 2016). The gene discussed is SERPINE1; the disease is pulmonary fibrosis.