A 'switch' that can turn off cancer has been identified by scientists from the University of Colorado.
They have discovered a molecule that actually triggers cell death, and they are convinced it can be developed into a treatment for cancer and other illnesses.
They found that the molecule called caspase, which was already well known for killing cells, could be used to target specific cancerous ones.
According to the researchers, if the finding can be turned into a treatment it would be a dramatic improvement on chemotherapy, which kills healthy cells, and well as the cancerous cells to treat the disease.
"Our findings initially seemed too good to be true," Professor Ding Xue, who led the study, said.
"We wound up looking at the results from a number of angles, including genetics, cell biology and biochemistry.
"Eventually we reached the only logical conclusions we could make.
"This is a completely novel finding, and all of the players in this story are well-known, well studied aspects of a very important process in our lives.
"The minute I saw the results, I knew it was a very, very important finding with wide implications," he added.
The experiments were conducted on a common, eyelash-sized nematode known as Caenorhabditis elegans, a popular laboratory organism for genetic and biomedical experiments.
The study has been published in the 12 March issue of Science.