Researchers are developing a technique to fight cancer cells using magnets, according to a new study published in Nature. The technique works by binding iron oxide nanoparticles to antibodies, which seek out and attach to tumor cells. By introducing a magnetic field, researchers can trigger natural cell death, known as apoptosis, which causes the cancer cells to die without harming surrounding healthy tissue. The researchers tested the new technique in vitro and on living zebra fish, and found that more than half of the cancer cells died while no healthy cells were harmed. However, the zebra fish experiments resulted in abnormal tail growth, so the new technology obviously has a long way to go before it can even be tested on humans.