AREG and asthma: Studies have found that AREG can be significantly expressed in human mast cells, basophils, and epithelial cells in rhinovirus-induced asthma, which may be related to the up-regulated expression of AREG in airway epithelial cells, which can cause airway remodeling.[35,36] Airway smooth muscle hyperplasia is one of the main features of tracheal remodeling.