APOE and Alzheimer disease: The literature also suggests that the upstream trigger of these regional brain atrophy differences is likely to be the observed differences in the regional distribution of NFTs in APOE4+ vs. APOE4− AD patients, with APOE4+ AD patients possessing a greater relative accumulation of NFTs in their medial temporal lobe (particularly in the entorhinal cortex) than APOE4− AD patients, and APOE4− AD patients possessing relatively more NFTs in their frontal and parietal lobes than APOE4+ AD patients.