Dvorak CC, et al. - Whether or not the potentially less toxic myeloablative conditioning regimen containing busulfan-fludarabine (Bu-Flu) is related to equivalent outcomes in cases with juvenile myelomonocytic leukemia (JMML) was determined. Bu-Flu was inadequate to provide disease control in patients with JMML who present for hematopoietic cell transplantation (HCT) with large burdens of disease. Additionally, it was noted that advances in molecular testing could enable better characterization of biologic risk, pre-HCT responses to chemotherapy, and post-HCT management.