Anna Schuh, MD, PhD, MRCP, FRCPath of University of Oxford, Oxford, UK, discusses the impact of genetic testing on treatment options in chronic lymphocytic leukemia (CLL). Clinical trial data show that 14% of patients with a NOTCH1 mutation do not benefit from the addition of antibody therapy, e.g. rituximab or ofatumumab to the chemotherapy backbone. Dr Schuh highlights that clinicians need to consider how to make the best use of the treatments options, avoiding potential side effects and freeing treatment resources for those patients who can benefit the most. Recorded at the 2016 International Workshop of the German CLL Study Group (GCLLSG) in Cologne, Germany.