 Patients suspected of having, or with prior biopsy proof of, a WHO grade II-IV central nervous system CNS glial tumors seen in the Surgical Neurology Branch, NINDS, will be considered for entry into this study. Tissue samples of tumor resected as part of standard care will be collected at surgery and preserved for research. Blood samples will also be collected. Blood will also be collected from anonymous normal volunteers who donate blood at the NIH Blood Bank; these anonymous donors will serve as controls. 