In the modern era of research into androgen actions in breast cancers, a great deal of focus has recently been placed on their actions in the triple negative subtype,22 partially through the appeal of androgen modulation as an effective and available therapeutic treatment for these difficult to treat cancers.23 Beyond this the potential of androgen modulation even in ER positive subtypes is once again being considered.24,25. This evidence concerns the gene ESR1 and cancer.