MAPT and Alzheimer disease: In addition to AD’s neuropathological hallmarks of amyloid plaques consisting of deposited Aβ peptides and neurofibrillary tangles consisting of hyperphosphorylated tau proteins, 60–90% of AD brains have evidence of cerebral amyloid angiopathy (CAA), cerebral small vessel disease and microvascular degeneration (Attems and Jellinger, 2014).