1. Division of Molecular Genetics, Massachusetts General Hospital Cancer Center, MGH East, Charlestown MA 02129.
2. Clinical Epidemiology Branch, Division of Cancer Etiology, NCI, NIH, Bethesda MD, 20892 and in the Division of Biostatistics and Epidemiology, Dana-Farber Cancer Institute, Boston, MA, 02115.
3. Division of Pediatrics, University of Texas M. D. Anderson Cancer Center, Houston, TX 77030.
4. Epidemiology and Biostatistics Program, Division of Cancer Etiology, NCI, NIH, Bethesda MD, 20892.
5. Department of Tumor Biology, University of Texas M. D. Anderson Cancer Center, Houston TX, 77030.
6. Division of Hematology-Oncology, The Children's Hospital, Dana-Farber Cancer Institute, Department of Pediatrics, Harvard Medical School, Boston MA, 02114.