While likely most of these traits are associated with AD genetic risk due to (horizontal) pleiotropic effects, the possibility that they may be mediators between AD genetic risk and AD can be considered broadly in terms of their convergence across different forms of AD, the consistency of APOE-ε4/APOE-ε2 trait and AD effects, and their changing effects with age. The gene discussed is APOE; the disease is Alzheimer disease.