Pax-7 in Chick Embryo (IMAGE) Yale University Caption Early chick embryo with Pax-7 (red) designating neural crest progenitor cells Credit Martín García-Castro Usage Restrictions with credit given 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.