At the 6th European Lung Cancer Conference (ELCC), held in Geneva, Switzerland, from 1316 April 2016, David Carbone, MD, PhD, from The Ohio State University Wexner Medical Center, Columbus, OH, discusses the characterization of tumor-infiltrating lymphocytes in resectable early stage non-small cell lung cancer (NSCLC) and the application of this understanding for the development of immunotherapy in early stage disease.