David Ellison is Chair of Pathology, Director of Neuropathology, and Joan and Roy Gignac Endowed Chair in Pathology and Laboratory Medicine at St. Jude Children’s Research Hospital. After studying for an M.A. in psychology at the University of Oxford, he graduated in medicine from the University of Cambridge, UK. Clinical training in general medicine and neurology in London preceded a Wellcome Trust research fellowship at Harvard University / Massachusetts General Hospital, where neurotransmitter alterations and neuronal loss in neurodegenerative diseases were the focus of his research in the laboratories of Dr. Flint Beal and Dr. E. P. Richardson. Encouraged by his studies in Boston to train in neuropathology, Dr. Ellison returned to England and positions in Oxford and Southampton. Initially, he took a faculty position in Southampton as a clinician–educator, but a developing academic interest in pediatric brain tumors led to an appointment as Professor in Neuropathology at the University of Newcastle and subsequent recruitment to St. Jude. Dr. Ellison is a Fellow of three British Royal Colleges – Physicians, Pathologists, and Paediatrics and Child Health. Current research interests include the molecular classification of ependymomas and low-grade gliomas and the development of clinical genomics and other precision medicine methodologies. Dr. Ellison has been an editor of two neuropathology textbooks: Greenfield’s Neuropathology and Neuropathology, a reference text of CNS pathology. He was a senior advisor / editor for the 2016 updated WHO classification of CNS tumors and is a member of the IARC/WHO Committee for the ICD-O: Tumors of the Central Nervous System.