The deposition of Aβ in the wall of leptomeningeal and cerebral blood vessels is the hallmark lesion of cerebral amyloid angiopathy (CAA)13, which develops not only linked to AD-related Aβ-production as shown in APP-transgenic mice14 but also in spontaneous hypertensive, stroke-prone rats (SHRSP)15,16 in the absence of amyloid plaques indicating a potential association between CAA and arterial hypertension. This evidence concerns the gene APP and Alzheimer disease.