Proteins from the Herpesviridae family have been found to interact with products of multiple AD susceptibility genes, namely, apolipoprotein E (APOE), phosphatidylinositol-binding clathrin assembly protein (PICALM), complement receptor 1 (CR1), and clusterin (CLU), which are associated with dementia [7,53,54]. Here, APOE is linked to Alzheimer disease.