SERPINE1 and Airway obstruction: Furthermore, it has been reported that α2‐macrogloblin levels are increased in obstructive lung disease, which may correlate with the increase in plasminogen observed in the BAL of ARDS patients.58., 59. However, the principal fibrinolytic inhibitor described in the pathogenesis of ARDS is plasminogen activator inhibitor 1 (PAI‐1), which is known to be elevated in severe acute respiratory syndrome coronavirus (SARS‐CoV) and ALI.11., 60.