A Myotube (IMAGE) Johns Hopkins Medicine Caption A myotube (red) formed from the fusion of multiple myoblasts generated from human embryonic stem cells. Nuclei marked in blue. Credit Courtesy Cell Press 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.