Genes central to the main female-biased cancers (melanoma, gastric and thyroid), breast cancer and ESR1, which encodes oestrogen receptor-α (ERα), include CDH1 (which encodes E-cadherin), CCND1 (cyclin D1), BRAF and KRAS (Fig. 1d and Supplementary Table 2). This evidence concerns the gene ESR1 and breast cancer.