C. elegans (IMAGE) KU Leuven Caption When their gene for the thyrotropin-releasing hormone (TRH) is deactivated, roundworms stay smaller than their healthy counterparts. Worms with extra TRH, by contrast, are larger. Credit KU Leuven Usage Restrictions Use with appropriate caption and credit 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.