In response to environmental signals, or inducer cytokines such as Interleukin-33 (IL-33), ILC2 can rapidly produce massive amounts of the type 2 cytokines IL-5 and IL-13 [18–21], which facilitate the development of type 2 inflammatory responses characterized by eosinophilia, airway remodeling, mucus hypersecretion, and airway hyperresponsiveness (AHR) [18–21]. Here, IL33 is linked to airway hyperresponsiveness.