1. Department of General Surgical Science, Graduate School of Medicine, Gunma University, Maebashi 371-8510, Japan
2. Division of Integrated Oncology Research, Gunma University, Initiative for Advanced Research (GIAR), Maebashi 371-8511, Japan
3. Department of Diagnostic Pathology, Gunma University Graduate School of Medicine, Gunma University, 3-39-22 Showa-machi, Maebashi 371-8511, Japan