MAPT and Alzheimer disease: Three groups with a total of 20 cases were assembled based on careful neuro-pathological inspection: 1) cognitively healthy control cases (n = 6) without any Aβ pathology or tau pathology, 2) AD cases with severe Aβ plaque pathology but no vascular deposits (no CAA) (n = 7) and 3) AD cases with severe nearly pure CAA type-1 pathology and a negligible amount of plaque pathology (n = 7).