Researchers are now using Polio Virus for a positive purpose: to attack cancer cells in the brain. Glioblastomas, the most common and lethal of all brain cancers, affect an estimated 240,000 people around the world per year. 12 of 20 patients with glioblastoma have responded well to the treatment wherein a modified inactive polio virus was used to infect tumor cells, setting off an immune response that lasts for several months until often the tumor is gone for good. Right dose and the right way of virus are used to get an immune response strong enough to fight the tumor but not so strong to harm the patient. All credits to team at Duke University for most exciting and most promising development in cancer research.