Modified poliovirus may be used to cure brain tumours in future. A study carried out by researchers at Duke University in Durham, North Carolina, USA , shows that the virus is effective in killing the cells of malignant gliomas, the most common and lethal type of brain cancer. The tumour cells produce particular kind of molecules, which attract the poliovirus. These virus then destroys the tumour cells. The poliovirus causes deadly disease called poliomyelitis. To avoid the occurrence of this disease while using the virus, the genes of the common cold virus have been introduced in it. The virus is currently being tested on monkeys. Researchers at the US National Cancer Institute are also developing an anti-tumour drug based on this process.