Dr. Louis directs the Pathology Service at MGH, which has about 90 faculty members, over 50 trainees and over 700 employees, and performs about 10 million laboratory tests, 80,000 surgical pathology evaluations and 60,000 cytologies each year. Dr. Louis’ own pathology practice and research focuses on brain tumors, with an emphasis on the application of molecular diagnostics to glioma classification. He has contributed over 300 original articles, reviews and chapters to the literature. His laboratory was the first to demonstrate that molecular approaches could subdivide malignant gliomas biologically and that molecular approaches could predict the response of malignant gliomas to therapies. This work has resulted in worldwide adoption of molecular testing for brain tumor patient management. Dr. Louis has received many awards for his work including the Zulch Prize of the Max Planck Society. He served on the 2000 WHO Committee on the Classification of Tumours of Nervous System. He also co-chaired and was the primary editor for the 2007 WHO Classification of Tumours of the CNS. He served as chair of the Scientific Advisory Panel of the Brain Tumor Society, on the Board of Directors of the Society for Neuro-Oncology and on editorial boards of more than 10 journals. Dr. Louis is an editor of the 8th edition of Greenfield’s Neuropathology, the standard international reference in neuropathology, and first author of the AFIP Fascicle on Non-Neoplastic Diseases of the CNS. He was also co-chair of the Brain Tumor Progress Review Group at NIH and was founding chair of the Cancer Biomarkers Study Section at NIH.