Tracy Batchelor is the Chair, Department of Neurology at Brigham and Women's Hospital, Co-Leader of the Neuro-Oncology Program at the Dana-Farber/Harvard Cancer Center, and the Miriam Sydney Joseph Professor of Neurology at Harvard Medical School, Boston, USA. He has spent his career focused on malignant haematological diseases that involve the central nervous system and co-founded the International Primary CNS Lymphoma Collaborative Group. Joshua P. Klein is Vice Chair for Clinical Affairs and the founding Chief of the Division of Hospital Neurology in the Department of Neurology at Brigham and Women's Hospital, and Associate Professor of Neurology and Radiology at Harvard Medical School, Boston, USA. He specializes in hospital neurology and diagnostic neuroimaging. He has served on the Board of Directors of the Neurohospitalist Society and the American Society of Neuroimaging for many years and is Editor-in-Chief of the journal The Neurohospitalist. He is a Fellow of the American Neurological Association, the American Society of Neuroimaging, and the American Academy of Neurology. Lisa M. DeAngelis is Physician-in-Chief and Chief Medical Officer at Memorial Sloan Kettering Cancer Center (MSK), New York, USA, where she holds the Scott M. and Lisa G. Stuart Chair. She served as chair of the Department of Neurology from 1997 to 2018, and co-founded MSK's Brain Tumor Center. Dr. DeAngelis specializes in brain cancer and the neurological complications of cancer treatment, including cognitive impairment and stroke, and her own research has focused on primary brain tumors. Dr. DeAngelis is an elected member of the National Academy of Medicine, a fellow of the American Neurological Association, and former Vice Chair of the Board. She is also a fellow of the American Academy of Neurology, which in 2019 awarded her the organization's highest honor, the Wartenberg Lecture. Andrés José María Ferreri is the Deputy Director of the Haematology Unit and Director of the Lymphoma Unit at the San Raffaele Scientific Institute, Milan, Italy, and President of the Italian Lymphoma Foundation (Fondazione Italiana Linfomi). Dr. Ferreri is fully devoted to research on lymphomas and is an international leader in the field of extranodal lymphomas.