Leaky brains (IMAGE) University of California - Berkeley Caption Cross section of a fruit fly brain showing how substances from the blood (green) seep in after cytokines from a distant tumor break down the barrier between the bloodstream and the brain. Blocking the cytokine improved the health and survival of both fruit flies and mice with cancer and could do the same for human cancer patients. Credit Image by Jung Kim, UC Berkeley Usage Restrictions none License Original 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.