Cerebral amyloid angiopathy exhibited a striking ε4 dose-response (OR = 5.76, 95% CI: 4.20-7.96, p < 0.001; for ε4/ε4 compared to ε3/ε3), whereas arteriolosclerosis and atherosclerosis risk increased with age, independent of <i>APOE</i> haplotype. Here, APOE is linked to atherosclerosis.