Researchers at the Cancer Research UK Cambridge Institute at the University of Cambridge report that they have developed a new technique for identifying the different types of cells in a tumor. Developed in mice, the method allows them to track the cells during treatment, seeing which types of cells die and which survive. The scientists, who believe the approach is a step towards the development of new treatments to prevent relapse in patients, published their study “Clonal transcriptomics identifies mechanisms of chemoresistance and empowers rational design of combination therapies” in eLife.