Is it ensure, insure, or assure?
Canadian physician who with the Scottish physiologist John Macleod won a 1923 Nobel Prize for the discovery of the hormone insulin. Banting and his assistant Charles Best experimented on diabetic dogs, demonstrating that insulin lowered their blood sugar. Insulin was tested and proven effective on humans within months of the first experiments with dogs. In acknowledgment of Best's work, Banting gave him a share of his portion of the Nobel Prize.