1. Department of Hematology and Oncology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan;
2. Department of Immunology, Juntendo University Graduate School of Medicine, Tokyo, Japan;
3. Division of Hematologic Malignancies, Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA; and
4. Department of Biostatistics and Computational Biology, Dana-Farber Cancer Institute, Harvard School of Public Health, Boston, MA