The molecular underpinnings of treatment-resistant breast cancer, which includes insensitivity to antiestrogen regimens[3], and refractoriness to epidermal growth factor receptor-2 (HER2) inhibitors[4], have been intensely investigated, and linked to aberrant receptor tyrosine kinase signaling[5], enhanced drug efflux mechanisms[6], and defective immune recognition[7]. This evidence concerns the gene ERBB2 and breast cancer.