APP and Alzheimer disease: In this context, the APOE test can be utilized on diverse subjects, uncovering various implications: in patients with a family history of AD, the APOE test (along with an analysis of other AD genes such as PSEN1, PSEN2, and APP) can help estimate the recurrence risk for AD; in AD patients, candidates for mAbs therapy can predict adverse events (ARIA); in healthy individuals, regardless of a family history of AD, it can indicate their susceptibility to AD.