APOE and Alzheimer disease: Diet‐induced obesity (i.e., western diet) in 5xfAD/human APOE‐ε4+/+ mice exhibit a significant increase in amyloid deposits, Aβ burden, and reactive gliosis compared to 5xfAD/human APOE‐E3+/+; suggesting that there is an interaction between obesity and APOE in increasing AD pathogenesis (Moser & Pike, 2017).