Results from this project will define the types and frequency of specific mutations in children with newly diagnosed and relapsed/refractory leukemia in the Northeast region, and assess the impact of the genomic assessment on their clinical care. It will also assess the feasibility of this approach in a regional setting. Some leukemia may not have clear genomic changes that lead to sensitivity to a known targeted drug. We have tested the sensitivity of 200 pediatric leukemia patient samples using a large panel of drugs and will study if certain new genomic features of the leukemia can predict response to a particular compound. We will use data generated in this proposal to inform future targeted therapy trials for children with leukemia with the long-term goal of precise, safe, and more efficacious therapies for children with these disease. Development of novel, targeted therapies to treat pediatric patients with leukemia is essential to continue to improve survival and decrease toxicities of treatment.