bbc.com/news/health-61150771 Scientists say they have identified urine bacteria which are linked to aggressive prostate cancer.
The discovery might provide new ways to spot and even prevent these dangerous tumours, experts hope.
It's too soon to say if the bacteria might cause the cancer, rather than just be a helpful marker.
The University of East Anglia team which found the link plan more work to see if clearing the infection with antibiotics might prevent bad tumours.
Bacterial infection is known to play a part in the development of other cancers - a bug called H. pylori can trigger stomach cancer, for example, and a course of antibiotics can get rid of this risk.