Despite access to some of the best possible medical care in the world, Senators John McCain and Edward Kennedy both died within 18 months of their diagnosis of glioblastoma, an aggressive form of brain cancer. While this deadly outcome typifies the nature of this disease, some glioblastoma patients see exceptional benefits from chemotherapy and survive beyond expectations. Why this happens has been revealed by researchers at the University of Minnesota in a new study published in the Proceedings of the National Academy of Sciences.