Minimal residual disease (MRD) is the small number of leukemic cells that remain after treatment and there are no signs of cancer. However, it is a major cause of relapse, and as such, MRD eradication is now a crucial focus in hematological cancer therapy. In this video, Peter Hillmen, MBChB, PhD, FRCP, FRCPath, from the University of Leeds and Leeds Teaching Hospitals NHS Trust, Leeds, UK, talks about the strength of MRD negativity as a predictive marker in chronic lymphocytic leukemia (CLL). Speaking from the British Society for Haematology (BSH) 2018 Annual Meeting in Liverpool, UK, Prof. Hillmen outlines the current issue of treating patients for longer than required and how achieving MRD negativity in these patients could prove to be the solution.