Killing tumours is a risky business; current methods like chemotherapy are very hard to target, leaving the patient exposed to risky and unpleasant side-effects. What is needed is a good accurate delivery system that gets the medicine to the relevent position effectively. Fortunately, University at Buffalo researchers have demonstrated a way of using magnetic fields to guide drug-loaded ‘nanocarriers’ to a tumour site before they unleash their payload. This could mean a lot less suffering for cancer patients in the future.