Metabolic dysregulation is a recognized characteristic of Alzheimer's disease17, evidenced by altered brain glucose uptake detectable via fluorodeoxyglucose (FDG)-based positron emission tomography (PET) scans18, by the APOE4 allele, which influences lipid metabolism19, and by metabolomics analyses showing metabolic changes in postmortem brain tissue correlated with AD pathology20,21. Here, APOE is linked to Alzheimer disease.