{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"Insulin is produced in the beta cells of the Islets of Langerhans in the pancreas. It is a polypeptide hormone that regulates carbohydrate metabolism. Apart from being the primary agent in carbohydrate homeostasis, insulin has effects on fat metabolism and changes the liver’s ability in storing or releasing glucose and processing blood lipids, and in other tissues such as fat and muscle. The amount of insulin in circulation has extremely widespread effects throughout the body."}]},{"type":"paragraph","children":[{"type":"text","value":"The presence of insulin in the cytoplasm of Islet Tumors is the most reliable indication of functional Insulinomas. Defective insulin storage occurs in Insulinomas; therefore, many sections of the tumor should be stained with both insulin and C-peptide."}]}]}