1 Department of Hematopoietic Tumor, Saitama Medical University International Medical Center, 1397-1, Yamane, 350-1298, Hidaka-City, Saitama-Pref, Japan. tsukasak@saitama-med.ac.jp.
2 Laboratory of Hematoimmunology, School of Health Sciences, Faculty of Medicine, University of the Ryukyus, 207 Uehara, Nishihara-cho, Okinawa, 903-0215, Japan.