Type 2 cytokines, including IL-4, IL-13, and IL-31; keratinocyte-derived TSLP and IL-33; and type 2 immune cells, including Eos, BS, MC, and Th2 cells, along with elevated serum IgE levels, play critical roles in the pathogenesis of AD and ACD (2, 4, 21, 31, 32). Here, IL4 is linked to Alzheimer disease.