ESR1 and neoplasm: This score was also significantly higher in the basal subtype (Wilcox test P < 1e−50, Fig. 7a), and correlated with poor clinical outcome (HR = 1.46 (95%CI: 1.32–1.62), P = 6e−13, Fig. 7b), which remained significant in a multivariate analysis adjusted for ER-status, grade, age, stage, and tumor size (HR = 1.26 (95%CI: 1.10–1.43), P = 0.0006, Supplementary Table 2).