APOE and Alzheimer disease: Furthermore, the AUCs of combination of CBF and ATT of 7-delay, sex, age, APOE ε4 carrier status, and educational years (as a composite biomarker) were higher than those mentioned above (AUC = 0.98, p < 0.001 for AD/NC comparison; AUC = 0.96, p < 0.001 for AD/MCI comparison; and AUC = 0.90, p < 0.001 for MCI/NC comparison) (Figure 1D and Supplementary Table 2).