Koala retrovirus (KoRV) causes cancer in koalas with up to 40% of captive animals dying from lymphoma. To make things complicated, many koalas are born with the virus, making it really hard to control control. We plan to set up diagnostic testing for koalas in European zoos, so we can monitor their KoRV status. This will let us predict which koalas might get cancer, and help us improve population health and plan breeding programs."