Every cell in the human body contains a "kill code" which can be triggered to cause its own self-destruction.

That's the discovery made by researchers at Northwestern University, Illinois, who believe it could be utilized for the future fight against cancer.

Specifically, they predict malignant cells could be encouraged to "commit suicide" without toxic chemicals pumped into the body.

Currently, as soon as the cell's inner bodyguards sense it is mutating into cancer, it self-activates the kill code to extinguish itself.

Embedded in ribonucleic acids, scientists estimate these evolved more than 800 million years ago in part to protect the body from diseases.

'Now that we know the kill code, we can trigger the mechanism without having to use chemotherapy and without messing with the genome,' said lead author Marcus E. Peter, the Tomas D. Spies Professor of Cancer Metabolism at Northwestern University Feinberg School of Medicine.

'We can use these small RNAs directly, introduce them into cells and trigger the kill switch.'

'My goal was not to come up with a new artificial toxic substance,' he added. 'I wanted to follow nature's lead. I want to utilize a mechanism that nature designed.'