The results in these studies show a consistent pattern of cytokine levels in the SC; the most pronounced differences between healthy and AD skin were found for the cytokines of innate immunity (decrease in IL‐1α and increase in IL‐1β and IL‐8 in AD) and for Th2 chemokines CCL17 and CCL22 (increased in AD). This evidence concerns the gene CCL22 and Alzheimer disease.