Much like shoelaces or dangly necklaces, DNA strands can tangle up in unruly knots. Specialized enzymes keep DNA organized when cells divide, so the cells split smoothly and don’t get stuck. But in tumor cells, this failsafe allows cancer to spread. Now, scientists at the Okinawa Institute of Science and Technology Graduate University (OIST) have learned how this mechanism works in fission yeast and how it might be undermined in human cancer.