1. Field of Drug Discovery Research, Faculty of Advanced Life Science, Hokkaido University, Sapporo, 001-0021, Japan
2. WPI Immunology Frontier Research Center, Osaka University, Yamada-oka 1-3, Suita, Osaka 565-0871, Japan
3. Department of Anatomy, Hokkaido University Graduate School of Medicine, Sapporo, 060-8638, Japan