Scientists have "trained" a virus to recognise ovarian cancer cells - and destroy them.
Reprogrammed viruses are already used in gene therapy to treat diseases.
But the research team led by Cardiff University says this one can do its work without affecting healthy cells.
They hope treatment could be a future possibility and also be used to treat other cancers such as breast, pancreatic, lung and oral.
Dr Alan Parker from Cardiff University's school of medicine said: "In cancer treatment, up until now reprogrammed viruses have not been able to selectively recognise only the cancer cells and would also infect healthy cells, resulting in unwanted side effects.
"We've taken a common, well-studied virus and completely redesigned it so that it can no longer attach to non-cancerous cells."
Instead, the respiratory virus seeks out a specific marker protein called αvβ6 integrin, which is unique to certain cancer cells, allowing it to invade them, said Dr Parker. BBC.
