Brain Tumor Stem Cells (IMAGE) Washington University School of Medicine Caption Brain tumor stem cells (orange) in mice express a stem cell marker (green). Researchers at Washington University School of Medicine in St. Louis are studying how cancer stem cells make tumors harder to kill and are looking for ways to eradicate these treatment-resistant cells. Credit Yi-Hsien Chen 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.