TSLP and allergic disease: Activation of group 2 innate lymphoid cells (ILC2s) by epithelium‐derived cytokines such as TSLP, IL‐7, IL‐25, IL‐33, and also IL‐4 induces the production of type 2 cytokines including IL‐5, IL‐9, IL‐13, and epidermal growth factor receptor (EGFR) ligand amphiregulin (AREG) for leading innate type 2 immunity.18, 19, 20 In this context, the intensity of activation of downstream signaling molecules and pathways may be strongly associated with the development of allergy.