Breast cancer: Scientists hail 'milestone' genetic find
2 May 2016 Last updated at 21:39 BST
Scientists say they have a near-perfect picture of the genetic mutations that cause breast cancer.
The study, in the journal Nature, has been described as a hugely significant moment in cancer research. It is hoped the analysis could help unlock new ways of "tailoring treatments" for breast cancer.
Dominic Hughes reports.