1. Radiation Effects Research Foundation, Hiroshima and Nagasaki, Japan;
2. Hirosoft International, Eureka, California;
3. Department of Hematology and Oncology, Hiroshima University, Hiroshima, Japan;
4. Hiroshima A-bomb Survivors Relief Foundation, Hiroshima, Japan;
5. Hiroshima Red Cross Hospital and Atomic-Bomb Survivors Hospital, Hiroshima, Japan;
6. The Japanese Red Cross Nagasaki Genbaku Hospital, Nagasaki, Japan;
7. Graduate School of Public Health, Teikyo University, Tokyo, Japan;
8. Department of Hematology, Nagasaki University, Nagasaki, Japan; and
9. Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, Maryland