Molecular Structures (IMAGE) University of Southern California Caption Researchers use powerful X-rays to reveal molecular structures at the site where drug compounds interact with cell receptors. These structures help point the way to designing medicines of the future. Credit Greg Stewart/SLAC National Accelerator Laboratory Usage Restrictions Use caption and credit information. 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.