Because imipramine and olanzapine are completely different drugs with regard to their structures, designed mechanisms of action, and current approved clinical indications, and their only common link is our discovery of their shared ability to block the apoE4-catalyzed polymerization of Aβ into neurotoxic fibrils, these findings validate this mechanism as an essential contribution of apoE4 to AD. Here, APOE is linked to Alzheimer disease.