Islets from type-2 diabetic patients contained a threefold elevated fraction of β-cells incapable of secreting any of the major pancreatic hormones and deficient in insulin, but expressing synaptophysin and aldehyde dehydrogenase 1 isoform A3 (ALDH1A3)44. The gene discussed is ALDH1A3; the disease is type 2 diabetes mellitus.