Project Summary To continue to make progress for pediatric oncology patients, we need to perpetuate the pool of talented and trained pediatric oncology-hematology physician-scientists who will make relevant discoveries and provide investigative leadership. This has become ever more challenging in the field of pediatric oncology, as there continues to be a shortage of young investigators with extensive laboratory research expertise. Fortunately, we are able to attract candidates willing to spend the time in the laboratory under the tutelage of outstanding investigators who are able to inculcate them with the culture of research that predominates at Johns Hopkins Medical (JHM) and the National Cancer Institute (NCI), despite the current challenging funding climate. This grant, institutional funds, and additional funding obtained by many trainees after two years in the laboratory allows the large majority of trainees to continue for at least three years, with many staying on at the Instructor level for additional time until they are fully ready to establish their own laboratory. In the current funding period (07/2018 – 09/2022), this grant has supported superb laboratory research training for an outstanding group of 17 physician-scientists (12 MD and 5 MD/PhD) who have demonstrated a high degree of productivity and commitment to careers in cancer research. Three of the MDs enrolled in a PhD graduate program while also receiving T32 training, and we anticipate more will do so in the future. This application seeks continued support for 8 interdisciplinary postdoctoral research positions per year. On average, we anticipate that 3 new trainees will be appointed to this T32 Program each year. These highly selected physician-scientists will have completed the clinical year of their fellowship. These strongly qualified trainees will be provided intensive three-year research experiences that will prepare them for careers in cancer research. Trainees work on projects relevant to the full range of childhood cancers, in the laboratories of leading scientists. Areas of faculty research expertise include pediatric leukemias, lymphomas, sarcomas, brain tumors, neuroblastoma, cancer genetics and epigenetics, cancer immunotherapy, stem cell transplantation, and small molecule drug development. The T32 trainees will receive extensive mentorship, not only from their primary laboratory mentor but also from the T32 Executive Committee and members of their Scholarship Oversight Committee, will participate in grant-writing workshops and have their grants reviewed by a T32 faculty committee, and will receive instruction in biostatistics, the responsible conduct of research, and additional topics in courses selected by the trainees. They will be provided career guidance via presentations from former T32 trainees now pursuing pediatric oncology research careers in academia, industry, and government, will be given the opportunity to present their research in multiple forums ...