We don't really understand why they are there but they appear to be associated with more aggressive forms of the disease. (newscientist.com)
For years, scientists have observed that tumor cells from certain breast cancer patients with aggressive forms of the disease contained low levels of mitochondrial DNA. (sciencedaily.com)
Now, nearly a quarter century later, there's something that helps some people with the most aggressive form of the disease. (sciencenews.org)