Understanding how normal tissues give rise to cancer is crucial for improving prevention and early detection of this deadly disease. Over the past two decades, the genomic profiles of most types of invasive cancer have been catalogued; however, similar profiling of normal tissues presents a unique set of challenges. Cancer tissues are often abundantly available from biopsies or surgery, but samples from normal tissues tend to be much smaller, and specimen-collection practices are less well established, making it hard to gather high-quality material. Writing in Nature, Moore et al.1 overcome these challenges and successfully catalogue cancer-driving mutations in normal endometrial glands….
