IL31 and Alzheimer disease: On the other hand, nine of the studies either proposed IL-33 or its downward products as a possible target for future therapies [26,31] or suggested a possible role of IL-33 as a causative agent of AD lesions [24,25,27,30,32], especially since pruritus is one of the main components of this condition and IL-33 is intimately linked to IL-31, another cytokine that is currently studied as a potential factor of the itching [69].