APOE and Alzheimer disease: The Prospective Imaging Study of Aging: Genes, Brain and Behaviour (PISA)32, is a multimodal study including amyloid PET scans that studies midlife aging (mean age 61, range 49–73), with a focus on individuals at high genetic risk of developing AD (APOE ε4 positive as well as those with high polygenic risk scores, AD-PRS).