1. Environmental and Cancer Epidemiology Area; National Center of Epidemiology; Instituto de Salud Carlos III; Madrid Spain
2. Consortium for Biomedical Research in Epidemiology and Public Health (CIBER of Epidemiology and Public Health); Centro de Investigación Biomédica en Red de Epidemiología y Salud Pública (CIBERESP); Madrid Spain
3. Division of Molecular Diagnostics of Oncogenic Infections, Infection, Inflammation and Cancer Program; German Cancer Research Center (DKFZ); Heidelberg Germany
4. Department of Microbiology; Ramón y Cajal University Hospital (IRYCIS); Madrid Spain
5. ISGlobal; Centre for Research in Environmental Epidemiology (CREAL); Barcelona Spain
6. IMIM (Hospital del Mar Medical Research Institute); Barcelona Spain
7. Universitat Pompeu Fabra (UPF); Barcelona Spain
8. Department of Clinical Sciences; Faculty of Medicine; University of Barcelona; Barcelona Spain
9. Cancer Prevention and Control Program; Catalan Institute of Oncology-IDIBELL; Hospitalet de Llobregat Spain
10. The Research Group in Gene; Environment and Health Interactions (GIGAS); University of León; León Spain
11. Faculty of Health Sciences; Area of Preventive Medicine and Public Health; Department of Biomedical Sciences; University of León; León Spain
12. Public Health Division of Gipuzkoa; BioDonostia Research Institute; San Sebastián Spain
13. Instituto de Salud Pública de Navarra - Navarra Institute for Health Research (IdiSNA); Pamplona Spain
14. IUOPA; University of Oviedo; Oviedo Spain
15. IDIVAL; University of Cantabria; Santander Spain
16. Gastroenterology Department; Sagunto University Hospital; Sagunto Spain
17. Gastroenterology Department; La Fe University and Politecnic Hospital; Valencia Spain
18. Centro de Investigación en Recursos Naturales, Salud, y Medio Ambiente (RENSMA); Universidad de Huelva; Huelva Spain
19. Department of Epidemiology; Murcia Regional Health Council; IMIB-Arrixaca; Murcia Spain
20. Instituto de Investigación Biosanitaria de Granada (ibs.GRANADA); Granada Health Research Institute (ibs.GRANADA); Granada Spain
21. Department of Preventive Medicine and Public Health; University of Granada; Granada Spain
22. Cancer Epidemiology Research Program; Catalan Institute of Oncology-IDIBELL; L'Hospitalet de Llobregat Spain
23. Spanish Network for Research in Infectious Diseases; (REIPI) Red Española de Investigación en Patología Infecciosa; Sevilla Spain