Daniel Drucker's path to a discovery that would transform millions of lives began not with a breakthrough - but a setback.
He had just arrived at Harvard Medical School in 1984 for a research fellowship, intending to focus on thyroid disease - an area he became interested in as a University of Toronto medical student and, later, as a fellow and resident at Toronto General Hospital.
His supervisor, Joel Habener, delivered the bad news: the lab was phasing out its thyroid program. Instead, Drucker would be tasked with studying glucagon, a hormone that regulates blood sugar.
