Pediatric acute myeloid leukemia (pAML) is a common type of cancer in children and is diagnosed in roughly 40 Canadian children each year. Although 90% of all children respond well to the initial treatment the cancer comes back for 20% of the children while being resistant to treatment, leading to a poor outcome. Current studies of treatment resistant cancers are not able to detect rare but important cells that form the cancer, which may be especially important in how treatment resistance occurs. Fortunately, new technologies allow for measurements from each of the thousands of individual cancer cells that form the tumor allowing us to detect rare cancer cells, including those that may result in treatment resistant disease. For the first time, we aim to use these technologies to focus on chemical properties of the DNA that influence how the DNA is interpreted, or read, by the cell. By studying patterns of these chemical properties in rare cancer cells and also normal cells we aim to learn if, and how, these patterns contribute to the phenomenon of treatment resistance in pediatric AML. With this knowledge, our ultimate goal is to prevent the formation of treatment resistant disease in this vulnerable population of patients.