SERPINE1 and asthma: The respiratory epithelial presence of specific isoforms of SERPINE1 (also called plasminogen activator inhibitor-1/PAI-1) has been examined as a possible asthma correlator [139], but the full body of literature yields a complex picture, with some research suggesting that that SERPINE1/PAI-1 dysregulation is of primary interest in cases reporting very specific polymorphisms of the protein (in particular the 4G/5G form) rather than as a general factor [140,141], while other studies consign its relevance to simple prediction of adverse corticosteroid side-effects [142,143].