Pre-Leukemic Stem Cells (IMAGE) Weizmann Institute of Science Caption Pre-leukemic stem cells (top) with both mutated and healthy copies of the RUNX1 gene already display some of the characteristics of acute myeloid leukemia. When the non-mutated copy of the gene is inactivated, disruptions in the spindle-assembly-checkpoint phase of cell division trigger cell death. Credit Weizmann Institute of Science 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.