1. Department of Pathology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
2. Department of Gynaecology, University Medical Center Groningen, 9700 RB Groningen, The Netherlands
3. Gastroenterology-Hepatology and Molecular Cell Biology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands
4. Institute for Pathology and Parasitology, Bulgarian Academy of Sciences, 1040 Sofia, Bulgaria
5. Department of Gynaecology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands