The analysis of APP751SL/+, an AD model with faster Aß plaque deposition, revealed qualitative (Fig. 3g) and quantitative (Fig. 3h) similar accumulation of IB4+ vascular anomalies, excluding the possibility of endothelial expression of the mutated form of PSEN1 as the cause of the vascular alterations in AD mouse models, and strongly suggesting that Aß plaques induce vascular disorganization. This evidence concerns the gene PSEN1 and Alzheimer disease.