APOE and amyloidosis: Genetic deletion of the murine ApoE gene (which is expressed as a single isoform) in mouse models overexpressing mutant forms of the human Aβ precursor protein (AβPP) results in inhibition of Aβ deposition or in a decrease in amyloid plaques (20, 21, 22, 23, 24, 25, 26, 27).