1. Department of Pathology, Kochi Medical School, Kohasu, Oko-cho, Nankoku City, Kochi 783-8505, Japan.
2. Department of Tumor Surgery, Kochi Medical School, Kochi, Japan.
3. Department of Laboratory Medicine, Kochi Medical School, Kochi, Japan.
4. Departments of Kochi Medical School, Kochi, Japan.