Guido Gerken has been the Director of the Clinic for Gastroenterology and Hepatology at UH Essen for 20 years. One of his particular merits is the establishment of the liver focus at University Hospital Essen. From 1988 to 1989, he completed his research fellowship in the “Molecular Biology and Hepatocarcinesis” department at the Pasteur Institute in Paris, one of the world’s leading basic research centers for biology and medicine. In 1990, he was appointed senior physician, and from 1990 to 1995 was a senior physician in Mainz. In 1998, he followed the call to the professorship for internal medicine in Essen and since then has been director of the Clinic for Gastroenterology and Hepatology. At the time of his appointment, the clinic specialized in research into inflammatory bowel disease. He continuously aligned it to conduct research into the liver and its disease, thus expanding it into a supraregional competence center for acute and chronic liver diseases. His main research interests are acute and terminal viral hepatitis, especially hepatitis B.