1 TGF-β and Cancer Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain; National Biomedical Research Institute on Liver and Gastrointestinal Diseases (CIBERehd), Instituto de Salud Carlos III, Madrid, Spain. Electronic address: jvaquero@idibell.cat.
2 Department of Gastroenterology, Hepatology and Infectious Diseases, University Hospital Duesseldorf, Medical Faculty of Heinrich Heine University, Moorenstr. 5, 40225 Duesseldorf, Germany. Electronic address: verena.keitel@med.uni-duesseldorf.de.