Endogenous RanBP9 protein levels were significantly increased by 3.5-fold in the hippocampus of 8-month-old APP/PS1 mice by immunoblotting (Figures 4a and b), consistent with our previous observations in 12-month-old J20 mice harboring the ‘Swedish' mutation and in AD brains.18, 19 Further, immunohistochemical analysis of APP/PS1 mouse hippocampus demonstrated greatly enhanced RanBP9 levels in the dentate gyrus (DG) and CA3 regions compared with WT littermates (Figure 4c). This evidence concerns the gene RANBP9 and Alzheimer disease.