In the METABRIC (Molecular Taxonomy of Breast Cancer International Consortium) cohort comprising 1977 breast cancers, Shamanna, Lu, Croteau et al. (2016) have shown recently that aggressiveness and adverse prognostic outcome in breast cancer patients were correlated with altered TOP1 and WRN expression in the tumor (Shamanna, Lu, Croteau, et al., 2016). Here, TOP1 is linked to breast cancer.