It is hoped new research at NUI Galway could improve the treatment of aggressive forms of breast cancer.
Scientists are looking at genetic factors that control how quickly the disease spreads.
They're concentrating on the "HERV K" gene that's linked to fast-growing tumours.
Dr Sharon Glynn from NUI Galway hopes the study will help streamline breast cancer treatments.
“We are hoping we can develop biomarkers for a start, so we can better understand which women have an aggressive disease versus having quite a non-aggressive one.
“If we know that we can better decide should people should people receive particular chemotherapies.”