MAPT and Mental deterioration: It is also important to emphasize that tau abnormality in the present study was defined based on medial temporal brain regions, which may partially account for the higher proportion of A-T + reported in our study, as compared with other recent PET imaging studies.4 Future studies should address whether APOEɛ4 genotype independently predicts prospective cognitive decline beyond Aβ-PET and tau-PET levels, given the association between APOEɛ4 genotype and both Aβ-PET and medial temporal tau-PET.