Consistent with the previous reports [11, 32], inflammatory cytokines IL-13, IL-31 and TNF-α were significantly elevated (Fig 4A, 4B and 4C statistically non-significant for IL-13 and TNF-α) whereas the pro-inflammatory cytokine IFN-γ and anti-inflammatory cytokine IL-10 were dramatically decreased in AD patient sera (Fig 4D and 4E). Here, IL31 is linked to Alzheimer disease.