We have previously demonstrated that Abca1 deficiency differentially affects AD-like phenotype in mice expressing human APOE4 or APOE3. To determine if ligand activated LXR can alleviate cognitive deficits in APP/E4/Abca1+/- mice, we treated five month old APP/E4/Abca1+/- mice with T0 for one month and the phenotype was examined at the age of six months. The gene discussed is ABCA1; the disease is Cognitive impairment.