CCL17 and Alzheimer disease: Third, the skin of Ctip2ep−/− mice is characterized by a dramatic upregulation of Th2-type cytokines and chemokines, including TSLP, CCL17, IL13 and IL4, all of which were induced early in Ctip2ep−/− epidermis, and are crucially involved in the initiation of pathogenesis in human AD [3], [7], [35].