ERBB2 and neoplasm: The real advance in this study is the discovery that upon using the ratio of the fate determinant ID4 and BRCA1 within a tumor as a derived measure, we were able to discriminate HR+HER2- tumors with low BRCA1 and no obvious phenotypic consequences, from those tumors in which the low BRCA1 was likely to be seen in the context of a high-grade, TNBC tumor, in a younger woman; all characteristics that are strongly associated with BRCA1 dysfunction.