IL4 and Alzheimer disease: The literature indicate that AD patients have (i) elevated blood eosinophil and serum IgE levels (mainly in extrinsic, not intrinsic AD), (ii) elevated levels of serum inflammatory cytokines (CKs) and chemokines (ChKs), such as IL-1β, IL-4, IL-6, IL-8 and tumor necrosis factor alpha (TNF-α), and (iii) infiltration of Th2 cells, mast cells and eosinophils in the skin [5,6,7].