A single nucleotide polymorphism (SNP) in NCAM2 (rs2212624) is associated with the development of late-onset AD (Kimura et al., 2006), while another SNP in NCAM2 (rs1022442) is associated with high Aβ levels in the cerebrospinal fluid (CSF) (Han et al., 2010), together suggesting that NCAM2 may be implicated in Aβ-dependent AD pathology. This evidence concerns the gene NCAM2 and Alzheimer disease.