CCL22 and Alzheimer disease: Our results demonstrated that the iMSC secretome alleviates the key immune reactions of AD, including the expression of Th2 cytokines (L‐4, IL‐13, IL‐31, IL‐22, CCL17, CCL22, and TSLP), as well as other inflammatory cytokines (TNF‐α, IL‐1β, IL‐6, and IFN‐γ).