APOE and Alzheimer disease: Reconstitution of CETP activity in mice will also be essential to address whether CETP inhibition is effective against CAA, parenchymal amyloid, or both, whether CETP inhibition can remove pre-existing vascular or parenchymal amyloid deposits, whether apoE isoform modifies CETP inhibition efficacy, whether CETP inhibition can reduce apoE-mediated tau neurodegeneration, and whether CETP inhibitors need CNS entry to affect vascular, amyloid, tau, and inflammatory pathways relevant to AD.