1. McMaster University, Hamilton, Ontario, Canada (H.J.S.)
2. European Commission, Joint Research Centre, Ispra, Italy (D.L., E.P., Z.S.)
3. St. Vincent's University Hospital, Dublin, Ireland (C.Q.)
4. German Cancer Society, Berlin, Germany (M.F.)
5. Iberoamerican Cochrane Center, Barcelona, Spain (P.A.)
6. Azienda Unitá Sanitaria Locale-IRCCS di Reggio Emilia, Reggia Emilia, Italy (P.G.R.)
7. Private Group Practice for Pathology, Lübeck, Germany (A.L.)
8. Umeå University, Umeå, Sweden (L.N.)
9. Radboud University Medical Centre, Nijmegen, the Netherlands (M.B.)
10. University of Athens Medical School, Athens, Greece (L.I.)
11. Queen Mary University of London, London, United Kingdom (S.W.D.)
12. University of Geneva, Geneva, Switzerland (B.B.)
13. National Screening Service, Dublin, Ireland (P.F.)
14. Cancer Registry of Norway, Oslo, Norway (S.H.)
15. IMIM (Hospital del Mar Medical Research Institute), Barcelona, Spain (X.C.)
16. CPO-Piedmont – AOU Cittá della Salute e della Scienza, Torino, Italy (L.G.)
17. Iberoamerican Cochrane Centre, Barcelona, Spain (C.C.)
18. Langford, North Somerset, United Kingdom (S.W.)
19. Cardiff University, Cardiff, United Kingdom (R.M.)
20. Universitá degli Studi di Milano, Milan, Italy (F.S.)
21. Radiologie am Theater, Paderborn, Germany (A.G.)