Researchers have discovered a new mechanism that explains why only some of the cells in a colon tumor respond to chemotherapy. The research team was able to establish that tumor cells dying off during chemotherapy communicate one last time with neighboring tumor cells to give them instructions on how to resist the therapy. The dying cells re-program the signalling cascades in the neighboring tumor cells in such a way that these are no longer vulnerable to chemotherapy. By doing so, the dying cells literally ensure that the tumor survives.