Triple negative breast cancer is one of the many subtypes of breast cancer characterised by the lack of expression of three key proteins known to respond to targeted therapies such as the oestrogen receptor (ER), progesterone receptor and Her2. Though sensitive to chemotherapy, these cancers are aggressive, have a poorer prognosis and are likely to form early metastases. Our preliminary data shows that raloxifene, a drug used to treat certain ER positive breast cancers, is also potently toxic against several ER negative breast cancer cells. Furthermore, a daily treatment by a low dose of raloxifene is sufficient to abolish ER negative tumour growth in an animal model. We aim to identify the mechanisms and pathways involved in raloxifene suppression of ER negative tumour growth and its ability to prevent metastasis formation. This study will provide data to advance efficient treatment of ER negative breast cancer and the appearance of metastases.