PICALM and Alzheimer disease: In addition, other genes linked to increased risk of AD include apolipoprotein E allele 4 (APOE 4), phosphatidylinositol-binding clathrin assembly protein (PICALM), endothelial nitric oxide synthase-3, alpha-2-macroglobulin, and clusterin (CLU aka APOJ), among others [57,58,59,60].