At the International Workshop on Non-Hodgkin Lymphoma (iwNHL) 2015 meeting, Francine M. Foss, MD, of the Yale University School of Medicine, New Haven, CT, chairs a discussion with Laurence de Leval, MD, PhD, of Institut universitaire de pathologie, Lausanne, Switzerland, Francesco d’Amore, MD, PhD of Aarhus University Hospital, Aarhus, Denmark, and Owen A. O’Connor, MD, PhD, Columbia University, New York, NY. Professor de Leval highlights recent discoveries in the molecular mechanisms of T-cell lymphoma development as well as the potential application of new biological markers for this patient population.