APOE and Mental deterioration: OI test may have limited value predicting amyloid and tau status when used alone, yet it is possible that an enhanced association between the two may be yielded when combined with other biologic markers discussed above (e.g., focusing on APOE ε4 carriers using tau PET imaging with olfactory region-based analysis), and it is still valuable in predicting cognitive decline and progression from MCI to AD dementia.