Tom Hemming Karlsen (MD, PhD) is a clinical specialist in internal medicine and gastroenterology working in Oslo, Norway. Dr. Karlsen graduated from medical school at the University of Bergen in 1997. In 2012 he was appointed professor of gastroenterology at the University of Bergen and in 2014 he was appointed full professor of internal medicine at the University of Oslo. Within the Oslo University Hospital he is Research Head of the Division of Surgery, Inflammatory medicine and Transplantation, and is also leader of the Norwegian PSC research center at the Department of Transplantation Medicine and Research Institute of Internal Medicine. Clinically, he works as a senior consultant within transplant hepatology at the Section of Gastroenterology at the Department of Transplantation Medicine.

Dr. Karlsen's research portfolio ranges from genetic epidemiology and applications of genomic technologies (e.g. dissecting the immunogenetic susceptibility to immune‐mediated gut and liver diseases), via translational research (e.g. biomarker studies) to clinical studies (e.g. liver transplantation). He is co-founder and former secretary (2010-2017) of the International PSC study group and has served as the coordinator of the Nordic Liver Transplant Registry from 2006-2014. He served as Secretary General of the European Association for the Study of the Liver (EASL) from 2017-2019, responsible for reorganizing several aspects of the organization governance. Since 2019 he has served as co-chair for the EASL-Lancet Commissions on liver disease in Europe.