SERPINE1 and acute respiratory distress syndrome: Plasma PAI‐1 levels have been reported as an independent risk factor for poor prognosis and mortality in ALI.59., 61., 62., 65., 66., 67., 68. Prabhakaran et al61 reported a significant increase in PAI‐1 antigen and activity in plasma and the edema fluid in ALI, with evidence of significant pulmonary production.61