PSEN1 and Alzheimer disease: Consistent with the other reports from human AD cases (4) and AD mouse models (49, 50), we show that vehicle-treated APP/PS1/E4 mice demonstrate significant and isoform-specific deterioration of cerebral amyloid pathology versus vehicle-treated APP/PS1/E2 or APP/PS1/E3 mice (see Figure 2, Figure 3, Figure 4).