Stressed yeast cells frantically reshuffle their chromosomes in a desperate last bid to find a combination that survives. This “panic” response enables them to rapidly evolve resistance to drugs.

The discovery might also apply to cancer, because cancer cells often have abnormal numbers and arrangements of chromosomes. Understanding one of the mechanisms by which cancers develop resistance to drugs could in turn open up new ways to combat cancer.

The key panic button driving the reshuffling is heat-shock protein 90 (Hsp90), which normally ensures that chromosomes are faithfully copied when cells divide and multiply. When Hsp90 is knocked out, the chromosomes get completely reshuffled. That’s normally a disaster, but in a desperate situation it’s a potential lifeline.