While serum tau levels (but not phosphorylated tau) and blood glucose levels were positively correlating in healthy controls, no such association was evident in EOAD patients.1 While further extensive and controlled cohort studies using more elaborate statistical methods including interaction analysis may be necessary to draw a definitive conclusion, these data are supportive of the potential role of tau in regulating glucose levels and impairment of that mechanism in AD patients. This evidence concerns the gene MAPT and Alzheimer disease.