IL25 and Alzheimer disease: IL-25 is produced by many cells, including epithelial cells, macrophages, eosinophils, mast cells, and basophils; however, a study focusing on acute and chronic allergic skin inflammation has identified keratinocyte-derived IL-25 as the dominant source of Il-25 for the upregulation of il-13. Not only does IL-25 play a part in AD-pathogenesis by inducing Th2 differentiation, but ex vivo studies have shown that IL-25 stimulation can directly lower filaggrin synthesis in keratinocytes [60,61,62,63].