SERPINE1 and asthma: PAI-1 plasma levels are increased in young children who had history of URI-induced repeated wheeze.[13] Human rhinovirus infection increases the production of PAI-1 in primary airway epithelial cells from subjects with asthma, and during an URI in subjects with asthma, nasal lavage and sputum PAI-1 levels increase.[12] These findings serve as in vitro and in vivo evidence of impact of respiratory viral infections on PAI-1 production in asthma.