Noerholm et al. BMC Cancer 2012, 12:22 http://www.biomedcentral.com/1471-2407/12/22 manuscript. This work was funded by American Brain Tumor Association Translational grant (JS, LB), NIH/NCI grant CA141226 (XOB), CA156009 (XOB) and NIH/NCI grant CA069246 (BC, AS and FHH). Brain Tumor Funders Collaborative and Harvard Catalyst (BSC). We gratefully acknowledge the Neuroscience Center PCR Core facility, which is funded by PHS grant P30NS045776. Author details 1Department of Neurology, Neurosurgery and Radiology, Massachusetts General Hospital and Program in Neuroscience, Harvard Medical School, Boston, MA 02114, USA. 2Exosome Diagnostics, Inc., Lasker Biomedical Research Building, Columbia University Medical Center, 3960 Broadway, Suite 540, New York, NY 10032, USA. 3Department of Neuroscience and Pharmacology, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands. 4Division of Neurological Surgery, UCSD School of Medicine, San Diego, CA 92103, USA. Authors’ contributions MN performed the data analysis and prepared the manuscript, LB and TL performed the qPCR analysis, AS participated in the array data analysis, BC and FH collected the samples and clinical data, LZ prepared serum from the clinical samples, JS, XOB designed the study and helped draft the manuscript. All authors read and approved the final manuscript. Competing interests J.S. and M.N. are inventors on the exosome technology used in this study which has been licensed to Exosome Diagnostics, Inc. They hold equity in, and are now employees of that company. Dr. Breakefield is on the Scientific Advisory Board of the company for which she receives cash compensation. None of the other authors have any competing financial interests to declare. Received: 30 October 2011 Accepted: 17 January 2012 Published: 17 January 2012 References 1. Dean BL, Drayer BP, Bird CR, Flom RA, Hodak JA, Coons SW, Carey RG: Gliomas: classification with MR imaging. Radiology 1990, 174:411-415. 2. Hartmann C, Hentschel B, Tatagiba M, Schramm J, Schnell O, Seidel C, Stein R, Reifenberger G, Pietsch T, von Deimling A, et al: Molecular Markers in Low-Grade Gliomas: Predictive or Prognostic? Clin Cancer Res 2011, 17:4588-4599. 3. 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