Zebrafish (IMAGE) Johns Hopkins Medicine Caption The pancreatic beta cells of a specially bred zebrafish glow yellow to indicate the production of insulin. The pancreatic cells not responsible for producing insulin glow red. Credit Credit: Johns Hopkins Medicine Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.