In addition, we also verify the CD4+/CD8+ cell ratio, total circulating IgE antibodies, expression levels of the previously reported-AD associated genes (PIAS1, RORA, SH2B1) and a panel of cytokines (IL-4, IL-10, IL-13, IL-31, IFN- γ, TGF- β1, TNF-α) in AD dogs compared to healthy controls. Here, IL31 is linked to Alzheimer disease.