Dirk Arnold is currently Head of the Department of Oncology and Haematology of the Klinik für Tumorbiologie in Freiburg, Germany. He is Professor of Medicine at the University of Hamburg, where he held the position as Medical Director of the University Cancer Center (UCCH) until 2012, and before as Assistant Professor and chair of the Gastrointestinal Cancer Unit at the Martin Luther University Halle-Wittenberg, Halle, Germany, where he also (as well as in Berlin) received his training as Medical Oncologist, and specialist in Palliative Care. Dr. Arnold’s main research interests include the treatment of gastrointestinal and genitourinary cancers, focusing on molecular-targeted therapies, immunotherapy, multimodal treatment strategies and early drug development. He is also interested in network research structures and methodology of clinical research and benefit evaluation procedures, as well as in palliative and supportive care. Dr. Arnold is the Chairman of the Colorectal Cancer Study Group of the Arbeitsgemeinschaft Internistische Onkologie (AIO) and is a member of the Task Force Colorectal Cancer and the Board of the Gastrointestinal Cancer Study Group of the EORTC, and is therefore involved in many ongoing phase I–III trials. He is a key member of several German and other international cancer societies, including the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO), where serves as Board Member and Section Editor for Gastrointestinal Cancers of the Guideline Committee.