1. Department of Molecular Biology, Sapporo Medical University, Sapporo, Japan
2. Division of Gastroenterology and Hepatology, St Marianna University School of Medicine, Kawasaki, Japan
3. First Department of Internal Medicine, Sapporo Medical University, Sapporo, Japan
4. Department of Public Health, Sapporo Medical University, Sapporo, Japan
5. Division of Molecular Diagnostic Pathology, Department of Pathology, School of Medicine, Iwate Medical University, Morioka, Japan
6. Division of Novel Therapy for Cancer, The Advanced Clinical Research Center, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan