TNF and Alzheimer disease: In the early stage of AD, keratinocyte-derived TSLP activates dendritic cells to induce the release of various chemokines, which leads to the expansion of the Th2 and Th22 cell populations and induces the release of IL-4, IL-5, IL-13, IL-22, and tumor necrosis factor alpha (TNFα) in large quantities [26].