PSEN1 and Alzheimer disease: These include increased vascular tortuosity and looping and kinking in AD [153, 161] and transgenic mice overexpressing APP [162, 163]; irregularities in capillary diameter in AD [157, 161, 164] and APP/PS1 mice [165]; abnormal patterns of branching, fusion and budding of vessels in AD [161] and APP23 mice [157, 163]; and an increase in degenerated ‘string’ vessels in AD [155, 166].