A protein has been discovered which could have major implications for cancer treatments, scientists have said.
Researchers at the University of Dundee described the protein as "molecular scissors" which repair damaged DNA in human cells, helping to prevent mutations that can lead to cancer.
John Rouse, of the university's College of Life Sciences, said the findings helped unlock a "major part of the puzzle".
The protein, known as FAN1, was found to "trim" pieces of DNA during repair to damage. Leftover pieces which can get in the way are removed by the protein.
Dr Rouse said: "Cells that do not have FAN1 are unable to repair DNA breaks and their DNA becomes irreversibly damaged and cells die. This underlines the fundamental importance of FAN1.
"Now that we have identified FAN1 and the role it plays in repairing DNA we can start to develop drugs that inhibit it.
"This may have a significant effect in cancer, primarily in helping to greatly enhance the efficacy of drugs used in chemotherapy treatments."
Most of the work was carried out by Craig MacKay, a PhD student in Dr Rouse's team in the Medical Research Council protein phosphorylation unit.
The research is published in the latest edition of the journal Cell. The work was funded by the Medical Research Council.