At the 6th European Lung Cancer Conference (ELCC), held in Geneva, Switzerland, from 1316 April 2016, Martin Reck, MD, PhD, from LungenClinic Grosshansdorf, Grosshansdorf, Germany, discusses ASSESS, a trial of the utility of circulating-free tumor DNA in the plasma for the detection of epidermal growth factor receptor (EGFR) mutation status in patients with advanced non-small cell lung cancer.