Both Alzheimer’s disease and cerebral amyloid angiopathy are strongly associated with the ε4 allele encoding the apoE4 isoform of apoE, and the clearance process of apoE4-Aβ complexes from brain tissue through capillary endothelial cells is less efficient than that of apoE3-Aβ and apoE2-Aβ [84]. Here, APOE is linked to Alzheimer disease.