The pancreas is a endocrine and exocrine organ. It produces hormones, such as insulin, and digestive enzymes, such as lipase. Loss of the pancreatic beta cells causes type 1 diabetes. The image has a labeled diagram of the parts of the pancreas and a histology image of a pancreatic islet. By OpenStax College [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons.
See related commentary
N. R. Gough, Engineering the immune system to treat diabetes. BioSerendipity (11 December 2017).