The presence of FOXC1, which was shown to be induced in luminal progenitor cells, suggests that germline BRCA mutations may cooperate with FOXC1 to induce tumorigenesis in the BLBC subgroup of BRCA-mutant breast cancer.21 The heterogeneity demonstrated especially in BRCA1 associated tumors may affect therapeutic options and requires further investigation. This evidence concerns the gene FOXC1 and breast cancer.