Glioblastoma multiforme (GBM, grade VI astrocytoma or just glioblastoma,) is a highly malignant (cancerous) type of tumor that occurs in the brain or spinal cord. As gliomas, these tumors form from glial cells. These tumors are very aggressive, meaning they grow and spread very quickly. Survival more than two years following diagnosis is rare. Even after aggressive treatment, the cancer commonly recurs. Glioblastoma treatment commonly involves surgical removal of the tumor(s), radiation, and/or chemotherapy. These tumors can sometimes be resistant to traditional treatments. Immunotherapy is being researched and has promising results. GBM is more common in males than in females.