MUC5AC and chronic asthma: Some mucins are important host defense strategies during influenza pathogenesis [76,77], and we showed that goblet cell metaplasia and associated mucin gene induction occur in the lungs of acute asthma and influenza co-morbid mice in which the airway epithelial lining is intact compared to influenza alone or chronic asthma and influenza models in which airway epithelial cell hyperplasia and necrosis occur [22].