The UCLA multidisciplinary pediatric oncology team will continue to participate in the cooperative clinical research programs of the Childrens Cancer Study Group (CCSG). We propose to admit eligible patients to the appropriate treatment, epidemiology and special studies of the Group. Our patient accrual has doubled in the 1st 2-3 years and, with the recent addition of an affiliate institution, we anticipate a further increase in our enrollment of patients onto therapeutic studies. We shall provide accurate and timely clinical data to the operations office, appropriate clinical research specimens to Group investigators, and prompt responses to requests for general information, critiques of manuscripts, and reviews of proposed studies. The UCLA faculty will provide scientific leadership to CCSG by serving as members and chairpersons of various study committees, strategy groups, task forces, and discipline committees. UCLA investigators have participated actively in the planning and leadership of treatment studies, biologic assessment studies, discipline committees, and strategy groups of CCSG. We shall continue to participate in and accept specific quality control responsibility for marrow transplantation studies of ALL, ANLL, and neuroblastoma. We shall continue to provide leadership for discipline committees in the areas of nursing, psychology and tumor immunology. Our record of leadership is evidenced by the publication of 23 abstracts, 20 peer-review papers, and 15 invited articles or reviews regarding our CCSG activities during the last five year grant period. Newly recruited faculty will provide leadership in molecular oncology and innovative approaches to the treatment of brain tumors. UCLA will continue to perform local and regional innovative pilot studies with the goal that promising therapeutic approaches will be adopted for Group-wide trail. Finally, UCLA shall continue to provide special clinical resources (e.g., in allogeneic and autologous bone marrow transplantation) and laboratory resources (e./g., immunologic analyses of pediatric malignancies and purging marrow of tumor cells to allow autologous marrow transplantation) for the accomplishment of Group-wide scientific goals.