1. Department of Gastroenterology, St George’s University Hospitals NHS Foundation Trust , London , UK
2. School of Immunology and Microbial Sciences, King’s College London , London , UK
3. AFA Crohn RCH , Paris , France
4. Department of Gastroenterology and Endoscopy, IRCCS San Raffaele Hospital and Vita-Salute San Raffaele University , Milan , Italy
5. Department of Gastroenterology, Hôpital Saint-Antoine , Assistance Publique-Hôpitaux de Paris, Paris , France
6. INSERM, Institut Pierre Louis d’Epidémiologie et de Santé Publique, Sorbonne Université , Paris , France
7. Department of Gastroenterology and Inserm NGERE U1256, University Hospital of Nancy, University of Lorraine , Vandoeuvre-lès-Nancy , France