The Manchester pediatric oncology unit is the third largest unit in the United Kingdom, with approximately 120 new referred cases per annum (10% of the U.K. total). Research activities include a gene therapy program, peripheral blood stem cell studies, the genetic epidemiology of childhood cancer, late-effects research (growth, body composition, pulmonary, quality of life), psychosocial studies, and clinical trial organization. Both the clinical oncology service and research activities involve close team coordination and collaboration with scientists both within and outside Manchester. A comprehensive pediatric hematology service is provided. The unit contains the second largest children's hemophilia service in the United Kingdom, serving 200 patients with congenital blood disorders. Twenty-five bone marrow transplants are performed each year (allogeneic, unrelated donor, autologous, and peripheral stem cell) for malignant and nonmalignant disorders. These activities are closely related to local, national, and international research groups.