Moreover, to show unique functions of the interleukin 4 receptors in vivo, studies in mouse models showed that for IL-4Rα and interleukin-13Rα1 (IL-13Rα1), interleukin-4-Rα/γC regulates Th2 cell responses, whereas the IL4-Rα/IL-13Rα1 type II receptor is particularly important for the induction of allergen-induced hypersensitivity in the lower airways and is thus crucial for the pathogenesis of type 2 asthma, suggesting that CRSwNP and type 2 asthma share some parts of the same pathogenesis [4, 21]. The gene discussed is IL4R; the disease is chronic rhinosinusitis with nasal polyps.