CD33 and Alzheimer disease: Recent large-scale GWA studies performed primarily in samples and populations of European ancestry detected genetic variants associated with AD in complement component (3b/4b) receptor 1 (CR1), clusterin (CLU, APOJ), bridging integrator 1 (BIN1), phosphatidylinositol-binding clathrin assembly protein (PICALM), EPH receptor A1 (EPHA1), CD33 molecule (CD33), membrane-spanning 4-domains, subfamily A, members 4 and 6E (MS4A4/MS4A6E), CD2-associated protein (CD2AP), and ATP-binding cassette, subfamily A, member 7 (ABCA7) [40–42].