1. Department of Gastoenterology and Hepatology, Hospital Ramón y Cajal, University of Alcalá, and Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (Ciberehd), Instituto de Salud Carlos III, Madrid, Spain
2. Section of Digestives Diseases, Yale University School of Medicine, New Haven, CT, and VA-Connecticut Healthcare System, West Haven, CT, USA