APOE and dementia: We started by targeting five brain regions from one healthy aged donor (90-year-old male without dementia, APOE ε3/ε3, and a post-mortem interval of 3.4 hours), including the hippocampus (HIP), cerebellum, substantia nigra (SN), caudate nucleus, and middle frontal gyrus (MFG) (Figure 1A, left).