GWASs have been a successful strategy to identify loci associated to a common trait, shedding light on disease pathways and for AD these include the following: (1) immune response (CR1, MSA4A/MSA7A, CD2AP, CD33, EPHA1, and ABCA7); (2) vesicles trafficking (PICALM and BIN1); (3) lipid metabolism (CLU and ABCA7); and (4) amyloid beta peripheral clearance (PICALM, BIN1, CD33, and ABCA7; http://www.alzgene.org/). This evidence concerns the gene CD33 and Alzheimer disease.