1. Departments of Pathology, University of Oulu, Oulu, Finland
2. Departments of Surgery, University of Oulu, Oulu, Finland
3. Medical Research Center Oulu, Oulu, Finland
4. Oulu University Hospital, Oulu, Finland
5. Upper Gastrointestinal Surgery, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden