Kostas Stamatopoulos, MD, PhD, Center for Research and Technology Hellas, Thermi, Greece, discusses whether there is one or multiple pathways to developing chronic lymphocytic leukemia (CLL). Dr Stamatopoulos also discusses the potential relationship between CLL and monoclonal B-cell lymphocytosis (MBL), and how this can develop our understanding of the disease. This interview was recorded during an online conference call with The Video Journal of Hematological Oncology (VJHemOnc).