Research Graphic (IMAGE) The Francis Crick Institute Caption AML cells reduce oxygen levels, causing increased NO production, which causes blood vessels to leak. Blocking NO restores leakiness and boosts the number of stem cells. Credit Diana Passaro 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.