Technological advances have made it increasingly cheap and easy to read the DNA sequence of entire genomes (ie, all of the genetic material of an organism or a biological unit like a tumor). However, our ability to meaningfully interpret the resulting large volume of data is still lagging. Now researchers have developed a new mathematical technique that allows them to filter out clutter in genetic data to identify recurring patterns, nicknamed COREs (for 'cores of recurrent events'). COREs identify locations in the human genome where DNA abnormalities occur, especially often during cancer. This analysis allows researchers to compare cancer tissue from different patients, different tumors from the same patient, and different cell types within the same tumor, to find out new information about how these cancer cells are related and how they change over time. These insights could help with prognosis and treatment decisions and might highlight genes that could be targets for new medications.