CCL17 and Alzheimer disease: Moreover, in the in vitro AD models using HaCaT cells or mouse primary keratinocytes stimulated with TNF-α/IFN-γ or IL-4, IMP treatment suppressed the gene expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and chemokines (CCL17 and CCL22) (Figure 5A and Supplementary Figure S4A).