One in three of us will get cancer at some stage in our lives. From the moment of diagnosis, the common cry is, 'why me?' We blame our genes, our environment and our lifestyle, but could we be overlooking another crucial cause of cancer? In Australia, a mysterious cancer cluster has led to an unusual investigation. Sixteen women working in one workplace have developed breast cancer. The majority are young, none have a family history of the disease and no environmental cause has been found for the illness. A team of scientists has begun to investigate if the cause could be a virus. It is a controversial idea, with extraordinary implications. In the United States, researchers are hunting a virus that triggers breast cancer in mice and asking, could it spread to people? In the United Kingdom, childhood leukaemia is under the microscope and infection is the prime suspect. 20% of all cancers worldwide are caused by infections. Now, across the planet, new evidence is emerging that links ...