1Gastroenterology Unit, Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy;

2Centre for Esophageal Diseases, Guy's and St. Thomas Hospital, London, UK;

3GSSI, Gran Sasso Science Institute, L'Aquila, Italy;

4Division of Gastroenterology, University Washington University School of Medicine, St. Louis, Missouri, USA;

5Division of Gastroenterology, Department of Surgery, Oncology and Gastroenterology, University of Padua, Padua, Italy;

6Division of Gastroenterology, Department of Internal Medicine (DIMI), University of Genoa, Genoa, Italy;

7Gastroenterology and Endoscopy Unit, Department of Pathophysiology and Transplantation, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, University of Milan, Milan, Italy;

8Guy's and St Thomas' Esophagogastric Centre, London, UK.

Correspondence: Nicola de Bortoli, MD. E-mail: [email protected].

*Edoardo V. Savarino and Nicola de Bortoli share joint last authorship.