Besides APoE4, nine other candidate genes, for example, ATP-binding cassette subfamily A member 7 (ABCA7), Myc box-dependent-interacting protein 1 (BIN1), CD2-associated protein (CD2AP), CD33, clusterin (CLU), complement receptor type 1 (CR1), ephrin type-A receptor 1 (EPHA1), membrane-spanning 4A (MS4A4E/MS4A6A), and phosphatidylinositol binding clathrin assembly protein (PICALM), have been identified as AD risk loci from a three-staged meta-analysis method based on establishing the differential frequency observed between AD patients and control non-dement groups [68, 69]. Here, CD33 is linked to Alzheimer disease.