Affiliation: | a Department of Immunology, Graduate School of Pharmaceutical Sciences Hokkaido University, Kita-Ku Kita 12 Nishi 6, Sapporo 060-0812, Japan b Department of Hematology and Oncology, Graduate School of Medicine, Osaka University, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan |