| 2008~ | Professor and Chair, Department of Medicine and Biosystemic Science, Graduate School of Medical Science, Kyushu University |
| 2005-2009 | Associate Professor, Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, and Department of Pathology, Harvard Medical School, Boston, Massachusetts |
| 2000-2004 | Assistant Professor, Department of Cancer Immunology and AIDS, Dana-Farber Cancer Institute, and Department of Pathology, Harvard Medical School, Boston, Massachusetts |
| 1994-1999 | Postdoctoral Fellow, (Laboratory of Irving L. Weissman, M.D.) Department of Pathology, Stanford University School of Medicine, Stanford, California |
| 1991-1993 | Clinician and Director of Division of Hematology, Sanshinkai General Hospital, Fukuoka, Japan |