IPA treatment suppressed DNCB-induced AD-like skin symptoms including infiltration of inflammatory and mast cells, elevated serum levels of IgE and TSLP and increased mRNA levels of TARC, MDC, TSLP, TNF-α, IFN-γ, IL-4, IL-5 and IL-13 in mice. The gene discussed is IL4; the disease is Alzheimer disease.