IL13 and Alzheimer disease: In addition, a bacterial artificial chromosome (BAC) transgenic mouse model that overexpresses the type 2 cytokines, IL-4, IL-5, and IL-13, spontaneously developed AD-like skin lesions due to an exaggerated type 2 response, e.g., high serum IgE levels, excessive immune cell infiltration (including eosinophils and lymphocytes) in the skin, and dermal thickening [42].