CCL17 and Alzheimer disease: qRT‐PCR analysis revealed significant decreases in AD biomarkers (IL‐4, IL‐13, IL‐22, IL‐31, CCL17, and TSLP) and inflammatory cytokines (TNF‐α, IFN‐γ, IL‐6, and IL‐1β) in the iMSC secretome treatment groups (5 and 20 mg/mL) compared to the DNCB group (p  < 0.05) (Figure 5A).