1. Colorectal Cancer Center, Kyungpook National University Medical Center, Kyungpook National University School of Medicine, Daegu, Korea.
2. Department of Pathology, Kyungpoook National University School of Medicine, Daegu, Korea.
3. Department of Surgery, Catholic University of Daegu School of Medicine, Daegu, Korea.
4. Department of Pathology, Catholic University of Daegu School of Medicine, Daegu, Korea.