Researchers at Georg-Speyer-Haus and Goethe University Frankfurt have discovered a new mechanism that explains why only some of the cells in a colon tumour respond to chemotherapy. The research team led by Professor Florian Greten was able to establish that tumour cells dying off during chemotherapy communicate one last time with neighbouring tumour cells to give them instructions on how to resist the therapy. The dying cells re-programme the signalling cascades in the neighbouring tumour cells in such a way that these are no longer vulnerable to chemotherapy. By doing so, the dying cells literally ensure that the tumour survives.