Blood Stem Cell Formation in Embryo (IMAGE) University of Edinburgh Caption This image shows the formation of blood stem cells inside the embryonic vessel called dorsal aorta. In green is shown secreted molecule called NOGGIN, which plays an important role in this process. Credit The University of Edinburgh 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.