From the International Workshop on Non-Hodgkin Lymphoma (iwNHL) 2018 meeting held in Nice, France, Francine Foss, MD, of Yale University School of Medicine, New Haven, CT, discusses the pathology and genetics of T-cell lymphoma with Jürgen Ruland, PhD, of Technical University of Munich, Munich, Germany. Prof. Foss and Prof. Ruland also expand on the nature of signalling pathways including TCR signalling and PD-1 expression in the disease, and how this impacts immunotherapies clinically investigated.