1. Ito Hospital, Tokyo, Japan.
2. Department of Public Health, Yamagata University Graduate School of Medicine, Yamagata, Japan.
3. Division of Diagnostic Pathology, Keio University School of Medicine, Tokyo, Japan.
4. Department of Hematology, JR Tokyo General Hospital, Tokyo, Japan.
5. Division of Social Communication System for Advanced Clinical Research, Institute of Medical Science, University of Tokyo, Tokyo, Japan.