ILC2s are able to rapidly produce large amounts of type 2 cytokines and growth factors, such as IL-5, IL-13, and AREG (34–36) to initiate type 2 immune responses, induce eosinophilic lung inflammation, airway hyperresponsiveness, mucus hypersecretion (39, 40), and to drive healing and fibrotic repair (35). Here, AREG is linked to airway hyperresponsiveness.