Epidemiological studies have suggested that cholesterol metabolism plays a role in Alzheimer’s disease (AD) pathogenesis and several of these genes, including LIPA and CH25H, have been investigated as possible risk factors for AD (Riemenschneider et al. 2004; Shownkeen et al. 2004; Shibata et al. 2006). The gene discussed is CH25H; the disease is Alzheimer disease.