In this sense, STAT3, MAPK, and mTORC1 pathways are also activated by leptin to enhance Th2 responses [98], the predominant form in AD [99], which release IL-4, IL-5 or IL-13, and increase the production of IgE, thus aggravating skin inflammation and skin barrier defects in AD [100]. This evidence concerns the gene IL4 and Alzheimer disease.