Nephrons (IMAGE) University of Edinburgh Caption This picture shows two nephrons growing in the laboratory. The green and red areas highlight cells that filter waste products from the blood. The blue section shows where urine is collected and taken away for excretion. Scientists have found that a molecule called beta-catenin instructs kidney cells to form these distinct areas of the nephron. Credit Dr Nils Lindstrom, University of Edinburgh Usage Restrictions This image may only be reproduced with the appropriate caption and credit. 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.