APOE and Dilatation of the cerebral artery: Patients with intracranial aneurysms had a significantly higher frequency of APOE E2/E2 genotype [odds ratio (OR) =9.51, 95 % confidence interval (CI) = 1.19, 76.04; P = 0.03] and APOE E2/E3 genotype (OR = 1.87, 95 % CI = 1.03, 3.40; P = 0.04) than healthy controls.