APOE and stroke disorder: APOE, by far the most important genetic risk factor for AD, is the main cholesterol transporter in the brain.27 The ε4 risk allele increases the risk of both dementia and CVD while the ε2 allele increases the risk of CVD while having protective effect on dementia.25 Using a subset of the study sample included here, Eriksson et al.3 showed that only carriers of the ε4 allele had an increase in dementia rate after suffering from a non-stroke CVD.