Who is credited with the invention of insulin?

Insulin, a hormone vital for regulating blood sugar, was a game-changer for people with diabetes. Before its discovery, Type 1 diabetes was essentially a death sentence. While several scientists contributed to the isolation and purification of insulin, John MacLeod played a crucial role in directing and overseeing the research team at the University of Toronto in the early 1920s. He provided the laboratory space and resources that made the breakthrough possible. Although Frederick Banting and Charles Best conducted the key experiments, MacLeod's leadership and expertise in carbohydrate metabolism were indispensable. The Nobel Prize in Physiology or Medicine was awarded to Banting and MacLeod in 1923 for the discovery of insulin. Banting shared his prize with Best, and MacLeod shared his with James Collip, another member of the team. So, while Banting and Best are often more widely known, MacLeod's contribution was significant enough to warrant the Nobel Prize, making him the correct answer. The other options are incorrect: Ian Wilmot is famous for cloning Dolly the sheep, Patrick Steptoe was a pioneer of in-vitro fertilisation, and Mary Peters is a celebrated athlete.