The high incidence of the symptoms characteristic of AD in people with DS is thought to be due to triplication of genes already demonstrated to be involved in AD pathology, including amyloid precursor protein (APP), beta secretase 2 (BACE2), SOD1, and S100 calcium-binding protein B (S100B), among others (Wiseman et al., 2015). The gene discussed is BACE2; the disease is Alzheimer disease.