Gimbel et al. showed that AD transgenic mice with intact PrPC expression exhibit deficits in spatial learning and memory, while mice lacking PrPC, but containing Aβ plaque derived from APPswe/PSen1DeltaE9 transgenes, show no detectable impairment of spatial learning and memory (Gertz et al., 2010). This evidence concerns the gene PRNP and Alzheimer disease.