A glioma is a form of brain tumor that is very frequent. Gliomas, which arise in the glial cells that surround and support neurons in the brain, account for around 33% of all brain cancers. Because gliomas grow within the brain’s structure and frequently interact with normal brain tissue, they’re called intra-axial brain tumors. Experts aren’t sure what causes brain tumors. In a small number of people, genetic disorders like neurofibromatosis or tuberous sclerosis can cause them. Exposure to radiation may also play a factor. No method is known for preventing gliomas or other brain tumors.