Sea Urchin (IMAGE) University of Portsmouth Caption What makes us so different to a sea urchin? Sea urchins have just one NCoR gene, while humans have two. Credit Free Stock Photos.com 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.