IL6 and Alzheimer disease: Parabiosis of APPswe/PS1dE9 mice with WT mice was found to result in the downregulation of inflammation by decreased levels of GFAP and CD45; reduction of proinflammatory cytokines including TNFα, IL-1, and IL-6; and the decrease of tau phosphorylation at Ser199 and Ser396 in AD mice [25].