Scientists from Helmholtz Centre for Infection Research are researching how salmonella kill tumours. Salmonella are regarded as bad guys. Hardly a summer passes without severe salmonella infections via raw egg dishes or chicken that find their way into the media. But salmonella not only harm us – in future they may even help to defend us against cancer. The bacteria migrate into solid tumours and make it easier to destroy them. Furthermore, in laboratory mice they independently find their way into metastases, where they can also aid clearance.