1. Ludwig Center for Cancer Genetics and Howard Hughes Medical Institutions, Johns Hopkins Kimmel Cancer Center, Baltimore, MD 21287, USA.
2. Department of Neurosurgery, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
3. Department of Otolaryngology-Head and Neck Surgery, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
4. Department of Pathology, Sol Goldman Pancreatic Cancer Research Center, Johns Hopkins Medical Institutions, Baltimore, MD 21287, USA.
5. Department of Neurosurgery, University of Texas M. D. Anderson Cancer Center and Baylor College of Medicine, Houston, TX 77030, USA.
6. Preston Robert Tisch Brain Tumor Center at Duke, Pediatric Brain Tumor Foundation Institute, and Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA.
7. Department of Neurology, School of Medicine, University of Sao Paulo, Sao Paulo, Brazil.