By the start of the 1920s, a treatment for diabetes, one of the world’s oldest diseases, had eluded the medical community for over two millennia. However, the prolonged wait was nearly at an end. In 1921, a research team from the University of Toronto isolated a new hormone from dogs. That hormone was insulin, the body’s regulator of blood glucose (sugar) levels. A year later, Indianapolis’ own Eli Lilly began mass producing purified insulin for public use, transforming diabetes from a death sentence to a chronic disease.