Birth of the Human Germ Cell Lineage (IMAGE) University of Cambridge Caption This is an 'embryoid' at the start of the appearance of SOX17 positive cells (green cells), which depict birth of the human germ cell lineage. Credit Walfred Tang, University of Cambridge Usage Restrictions For use in relation to this research only. 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.