1. Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland
2. Institute of Molecular Life Sciences and SIB Swiss Institute of Bioinformatics, University of Zurich, Zurich, Switzerland
3. Gastroenterology and Endoscopy Unit, Hospital of Cremona, Cremona, Italy
4. Division of Gastroenterology, Triemli Hospital, Zurich, Switzerland
5. Division of Pathology, Hospital of Cremona, Cremona, Italy
6. Institute of Surgical Pathology, University of Zurich, Zurich, Switzerland
7. Division of Pathology, Triemli Hospital, Zurich, Switzerland