Damage to the skin barrier function is known to be the main cause of Th1/Th2 immune imbalance, due to the Th2-mediated immune response, and pro-inflammatory cytokines, including IL-4, IL-5, IL-13 and IL-31 and it plays an important role in further eliciting the environment of AD through stimulation. The gene discussed is IL4; the disease is Alzheimer disease.