Scientists are a step closer to discovering why radiation causes cancer.
They have identified a molecule which appears to play a crucial role in protecting cells against radiation.

The discovery could have implications for the treatment of cancer, the UK researchers say, because targeting cancer cells with drugs to inactivate the molecule could make them much more sensitive to the effects of radiotherapy.

Exposing human cells to radiation sets off an emergency response system, which repairs mutated genes or kills off cells that have suffered irreparable damage.