Breast cancer is the most common cancer among Canadian women. One in nine women is expected to develop breast cancer in her lifetime, and one in 27 will die of the disease. Metastasis, or the spread of the tumour to another site, is the major cause of death. Notch receptors are cellular proteins required for normal growth and development. However an overproduction of an active component of Notch can cause abnormal cell growth, leading to tumour formation and the spread of cancer to distant sites. Iva Kulic is examining how another protein, called Slug, functions with Notch to promote breast cancer. Both Notch and Slug are found at high levels in some human breast cancers and are a sign of poor outcome. Slug prevents tumour cells from dying and allows them to detach from neighbouring cells and travel to other sites within the body – two key features in tumour development and metastasis. This research will explore whether reducing or eliminating the Slug protein will inhibit breast tumour growth and block the spread of cancer cells. Resolving whether Slug is essential in Notch-induced breast cancer could lead to new ways of preventing and treating the disease.