APP and Cognitive impairment: To determine whether apoE has isoform-dependent effects on hAPP/Aβ-induced behavioral alterations and cognitive impairments in aged female and male mice at 18 months of age, we crossed APP NL-F KI with E2, E3, and E4 mice to generate NL-F/E2, NL-F/E3, and NL-F/E4 mice.