Overall survival for children diagnosed with acute lymphoblastic leukemia (ALL) has dramatically improved over recent years due to optimization of dosing and timing of standard chemotherapeutics. However, this intensified treatment is associated with increased short-term side effects and long-term, irreversible toxicities, which occur in up to 25% of pediatric patients and include cognitive and developmental disabilities, infertility, damage to organs, and secondary cancers. In addition, subsets of patients are refractory to therapy or have disease relapse.