1. Department of PathologyKanagawa Cancer Center Yokohama 241‐8515 Japan
2. Division of Cancer Cell ResearchKanagawa Cancer Center Research Institute Yokohama 241‐8515 Japan
3. Center for Translational ResearchThe Institute of Medical Science HospitalUniversity of Tokyo Tokyo 108‐8639 Japan
4. Department of Hematology/Medical OncologyKanagawa Cancer Center Yokohama 241‐8515 Japan
5. Department of Molecular Pathology and GeneticsKanagawa Cancer Center Research Institute Yokohama 241‐8515 Japan