1. Department of Internal Medicine I; University of Bonn; Bonn Germany
2. Department of Pathology; University of Bonn; Bonn Germany
3. Department of Internal Medicine II; University of Bonn; Bonn Germany
4. Institute for Cell Biology; University of Bonn; Bonn Germany
5. Institutes for Molecular Medicine and Experimental Immunology; University of Bonn; Bonn Germany
6. Department of Liver and Biliopancreatic disorders; University of Leuven; Leuven Belgium
7. Gastroenterology Research Unit and Cancer Cell Biology Program; Mayo Clinic; Rochester MN