Although IL-13 plays a major role in mediating Th2 cell immunity, IL-4 plays a non-redundant role, and this is true in causing increased intestinal permeability.18,90,91 IL-4Rα blockade can attenuate food allergy in AD patients92,93 and improves the efficacy of peanut oral immunotherapy.94 Its effect on intestinal permeability has not been investigated. Here, IL4 is linked to Alzheimer disease.