Dr. David N. Louis is the Benjamin Castleman Professor of Pathology at HMS; chair of the Executive Committee on Research at MGH; and chair of the department of Pathology at MGH. Under his chairmanship, MGH Pathology has become a national leader in molecular diagnostics and pathology informatics, leading to a novel initiative in computational pathology. Dr. Louis’s own clinical neuropathology practice and research focuses on brain tumors, with an emphasis on the molecular basis of malignant gliomas and the application of molecular diagnostics to glioma classification. His work has contributed to worldwide adoption of molecular testing for the management of patients with these tumors.