In patients with AD, the expression and secretion of the AD-related cytokines interleukin (IL)-25, IL-33, thymic stromal lymphopoietin (TSLP), and the chemokines thymus and activation-regulated chemokine (TARC), macrophage-derived chemokines (MDC) and, regulated on activation, normal T cell expressed and secreted (RANTES) are increased in keratinocytes [10,11]. This evidence concerns the gene CCL17 and Alzheimer disease.