CD33 and Alzheimer disease: Whole-genome sequencing (WGS) and genome-wide association studies (GWAS) have revealed additional genetic loci associated with late-onset AD risk, including TREM2, BIN1, CLU, ABCA7, CR1, PICALM, MS4A6A, CD33, MS4A4E, CD2AP, EPHA1, and EXOC3L2/BLOC1S3/MARK4, among others (Guerreiro et al., 2013; Harold et al., 2009; Hollingworth et al., 2011; Jonsson et al., 2013; Lambert et al., 2009; Naj et al., 2011; Seshadri et al., 2010).