APOE and cerebral amyloid angiopathy: Several studies have demonstrated that ε4 variants within the apolipoprotein E (APOE) gene lead to higher risk of cerebral amyloid angiopathy and spontaneous ICH among patients who do not have underlying AVM.9,10 In this study, we tested the hypothesis that APOE ε4 variants are associated with higher risk of ICH among patients with known brain AVM.