Beyond fighting infection, the immune system has important roles in many systems in the body. To study the involvement of T cells and B cells, researchers often sequence their T cell and B cell receptors (TCRs and BCRs), which provide insights into their clonal diversity. However, even more useful would be to gather T cell and B cell receptor information together with the transcriptomic profile of their tissue sample of origin. Now, in a paper published in Nature Biotechnology, Dmitriy Chudakov and colleagues report a software tool that enables extracting TCR and BCR sequences from bulk RNA-seq data sets. Because RNA-seq data is already available for thousands of tumor samples, this method will allow revisiting those data sets to extract important information.