Tumor Spheroids (IMAGE) NASA/Johnson Space Center Caption Three-dimensional, multicellular tumor spheroids begin to form after exposure to real microgravity. Credit Team Daniela Grimm Usage Restrictions Team Daniela Grimm 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.