ABCA1 and Alzheimer disease: ABCA1 was more abundant in lysosome-enriched fractions in the AD group than in the NCI group within the APOE3/4 genotype but not in the APOE3/3 genotype (Fig. 2C, full blots are shown in Supplementary Fig. 3), supporting that more ABCA1 was trapped in lysosomes in APOE4 AD.