The presence of APOE ε4 allele is associated with greater amyloid deposition (Drzezga et al., 2009; Morris et al., 2010), alterations in brain function and glucose metabolism (Langbaum et al., 2009), as well as decreased level of Aβ42 in the CSF in patients with late MCI and AD and older adults with normal cognition (Vemuri et al., 2010; Risacher et al., 2013). The gene discussed is APOE; the disease is Alzheimer disease.