Cell (IMAGE) Washington University School of Medicine Caption Even in a healthy people, stem cells in the blood accumulate hundreds of mutations. When a cancer-initiating event occurs in one of these stem cells, it captures the genetic history of that cell, including the earlier mutations, and drives leukemia to develop. A schematic of that evolution is pictured above. Credit Joshua McMichael, The Genome Institute at Washington University in St. Louis Usage Restrictions Credit to Joshua McMichael at The Genome Institute at Washington University in St. Louis 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.