Recruiting patients into clinical trials tends to be a highly selective process, according to Frank Griesinger, MD, PhD, of the University of Göttingen, Göttingen, Germany. Choosing a very specific and selected patient population would not translate well for the real world population, and in this insightful interview recorded at the European Society for Medical Oncology (ESMO) 2018 Congress, in Munich, Germany, Prof. Griesinger states that data from such studies would be misleading, having a knock-on effect on the development of effective treatments for patients.