We don't really understand why they are there but they appear to be associated with more aggressive forms of the disease. (newscientist.com)
Ultimately, they hope to find proteins in blood that could alert doctors to patients with aggressive forms of breast cancer. (pnnl.gov)
Women with particularly aggressive forms of breast cancer could be identified by a test that predicts whether the disease is likely to spread to the brain. (sciencedaily.com)