Researchers have identified amyloid beta (Aβ) detected in blood to originate from peripheral tissues, and that the peptide acts on pancreaticβ-cells to suppress insulin secretion, thereby regulating blood glucose levels. The study, which urges us to be careful when using blood Aβ levels as a diagnostic marker for Alzheimer’s disease (AD), was published in the Proceedings of the National Academy of Sciences (PNAS).