Indeed, brain glucose hypometabolism is well-known to be present in Alzheimer’s disease (AD) itself (Herholz, 1995, 2014) and in conditions associated with increased risk of AD including mild cognitive impairment (MCI; Albin et al., 2010; Pagani et al., 2015), carriers of the apolipoprotein E4 (APOE4) allele (Mosconi et al., 2008a), a family history of AD (Reiman et al., 2004; Mosconi et al., 2007a), and type 2 diabetes (Baker et al., 2011). The gene discussed is APOE; the disease is Alzheimer disease.