1. Department of Surgery, County Hospital Ryhov, Jönköping, Sweden
2. Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
3. Department of Medical Sciences, Molecular Epidemiology, Uppsala University, Uppsala, Sweden
4. Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden
5. Department of Surgery, Linköping University Hospital, Linköping, Sweden