IL33 and asthma: Additionally, as a central part of the epithelial-mesenchymal trophic unit (EMTU), AECs are centrally involved in airway remodelling; they represent the target cells for most of those respiratory viruses that have been implemented in the initiation and exacerbation of asthma, and upon epithelial damage, they release factors favouring T2-type immune reactions such as IL-25, IL-33, and thymic stromal lymphopoietin (TSLP) [78].