A magnetic method of killing cancer cells has been developed by scientists in South Korea.
The technique uses a magnetic field to flip a "self-destruct" switch in tumours.
Researchers have demonstrated that the process works in bowel cancer cells and living laboratory fish. Programmed cell death, or apoptosis, is one of the body's ways of getting rid of old, faulty or infected cells.
In response to certain signals, the doomed cell shrinks and breaks into fragments. These are then engulfed and consumed by amoeba-like immune cells.
Often in cancer, apoptosis fails and cells are allowed to keep dividing uncontrollably.