The Pediatric Oncology Program at Emory University is the only comprehensive children's cancer center in Georgia and one of the largest of its kind in the Southeast. It serves a racially, ethnically, and socioeconomically diverse population from metropolitan Atlanta, the State of Georgia, and other states including Alabama, Arkansas, the Carolinas, Florida, and Mississippi. Since the inception of the Pediatric Oncology Group (POG), Emory is consistently one of the largest single-institution contributors to POG clinical and laboratory studies. Emory is a center for Phase I and pilot POG trials and has initiated numerous protocols that have subsequently been implemented by POG. The specific aims of the Emory POG Program are: l) to continue as a major source of patients for POG-sponsored Phase I, pilot, groupwide, and intergroup studies; 2) to provide leadership by its investigators as POG Study Coordinators, Co- coordinators, and Core Committee members; 3) to develop innovative institutional clinical trials on which to base future POG investigations; and 4) to maintain strong basic and translational research programs in pediatric oncology. To address these aims, Emory investigators are Coordinators for several major POG studies, including standard-risk new ALL (#9405), high-risk new ALL (#9006), salvage chemotherapy in relapsed neuroblastoma (#9140), and chemotherapy vs. autologous bone marrow transplantation (ABMT) in AML (#8821). Emory POG members actively participate in POG Core Committees, Subcommittees, and new protocol development. Institutional pilot studies include therapy of relapsed AML with idarubicin and chlordeoxyadenosine, treatment of relapsed solid tumors with high-dose busulfan/melphalan and ABMT, transplantation of haploidentical CD34+ cells for relapsed ALL or AML, and vincristine plus dose-escalated cyclophosphamide and infusions of peripheral blood-derived progenitor cells in refractory solid tumors. Complementary laboratory research activities include molecular biology of ALL (mechanisms of IL-6- mediated autocrine growth and aberrations in tumor-suppressor genes); in vitro sensitivity of leukemia cells to antineoplastic agents mid biological response modifiers; mechanisms of resistance of AML cells to alkylating agents; molecular neuro-oncology; and xenogeneic models to evaluate normal and neoplastic human hematopoiesis. Investigators at Emory are participating in the POG laboratory study of methotrexate metabolism by ALL cells (ALinC #16) and coordinate the study of alterations in p53 tumor-suppressor gene pathways in relapsed ALL (SIMAL #l0). Taken together, these activities of the Emory POG Program will continue to contribute to our knowledge of the biology, therapy, and prevention of neoplastic diseases in infancy, childhood and adolescence.