A KEY weapon in the body’s immune system armoury may play a major role in triggering cancer, new research published in the journal Nature Genetics suggests.
Scientists were surprised to find that the family of virus-fighting proteins produce gene defects linked to several cancers.
The discovery was especially unexpected because one of the main functions of the molecules is to protect DNA from attack by viruses.
The proteins, known as APOBEC cytidine deaminases, cause clusters of mutations that can outnumber all others associated with cancer, say the researchers.
They were found to account for more than two-thirds of some bladder, cervical, breast, head and neck, and lung tumour mutations.
All cancers are ultimately the result of mistakes in the genetic code that remain uncorrected. These can have a number of causes, including toxic chemicals and radiation.