Insulin

Insulin was discovered to control carbohydrate metabolism and alleviate symptoms of diabetes. Researchers isolated it from degenerated pancreas tissue, finding that it was produced inside the previously identified Islets of Langerhans, thus the name insulin, from the Latin word for island.
 Frederick Grant Banting Canada 1921 Insulin

Insulin was discovered to control carbohydrate metabolism and alleviate symptoms of diabetes. Researchers isolated it from degenerated pancreas tissue, finding that it was produced inside the previously identified Islets of Langerhans, thus the name insulin, from the Latin word for island.