Doctors believe they have found a way of identifying when and if breast cancer will spread to other regions of the body.
Scientists at Imperial College London found that high levels of a genetic modification called methylation on the CACNA2D3 gene acted as a molecular post-it note that flags up the possibility of tumours multiplying.
The research observed how the addition of methyl groups to the gene prevented it from inhibiting cancer development.
Lead author Dr Carlo Palmieri said: "The next stage is to repeat these findings in larger studies with patients to confirm whether analysing methylation of the gene could be a useful test."
Cancer Research's cancer information manager Dr Julie Sharp explained that this was just the latest advancement in the field of epigenetics - the study of how external modifications of the DNA change how genes are expressed.
According to the charity, breast cancer is the most common form of the disease in the UK.