On this day, 104 years ago, July 27, 1921 (June 23, 1921 in the lunar calendar), insulin was successfully separated. On July 27, 1921, Canadian doctor Frederick G. Banting and his collaborator Charles Best isolated a substance from the pancreas of dogs that eliminated the fatal symptoms of diabetes. The extract was named insulin by Dr. John McLeod of the University of Toronto. The doctor had encouraged Bantin and provided him with a laboratory. Insulin is expected to save the lives of many diabetic patients. Although they all strictly control their diet, they still face the threat of slow death.