IL13 and Alzheimer disease: Upon exposure to external stimuli, several epidermal-derived cytokines such as thymic stromal lymphopoietin, interleukin (IL)-33, and IL-25 are released and induce type-2 immune responses, leading to atopic skin inflammation.[6–8] In the acute phase of AD, many type 2 T-helper cells (Th2 cells), which produce cytokines, including IL-4, IL-5, and IL-13, migrate to lesion sites, suggesting that Th2 cells play an important role in the early inflammation observed in AD.