Herein, we provide evidence that the BD-L metagene may be enriched in clinically detectable breast cancer brain metastases and the metagene may implicate sporadic breast cancers across the conventional receptor and mutational status classifications that may benefit from a PARP inhibitor-based therapy while also identifying triple negative and BRCA1-mutant cancers that may prove refractory to treatment. The gene discussed is BRCA1; the disease is cancer.