1. Department of Medicine and Clinical Science; Gunma University Graduate School of Medicine; Maebashi Gunma Japan
2. Division of Blood Transfusion Service, Faculty of Medicine; Gunma University Hospital; Maebashi Gunma Japan
3. Leukemia Research Center; Saiseikai Maebashi Hospital; Maebashi Gunma Japan
4. Gunma University School of Health Sciences, Faculty of Medicine; Gunma University; Maebashi Gunma Japan