For example, in breast cancer, high CES tumours are enriched for high-grade (P<0.0001, Kruskal–Wallis test; Supplementary Fig. 3; Table 2), ER− and PR− status (P<0.0001, Wilcoxon rank-sum test; Supplementary Fig. 4; Table 2), and more aggressive molecular subtypes (basal like, HER2+ versus luminal; P<0.0001, Kruskal–Wallis test; Supplementary Fig. 5; Table 2). This evidence concerns the gene ERBB2 and breast cancer.