IL4 and Alzheimer disease: Indeed, desmoglein (DSG)-1 was found to be downregulated in the lesional epidermis of AD patients, and its expression could also be suppressed experimentally in primary human epidermal keratinocytes by a highly “AD-relevant” [145,146] cytokine cocktail (IL-4 and IL-13; both at 50 ng/mL for 48 h) [278].