ERBB2 and breast cancer: Moreover, our data indicate that disrupting BAG-1 function might be a useful therapeutic strategy for targeting HER2+ breast cancers in combination with trastuzumab, but also for those cancers that are refractory to trastuzumab, and emphasise the need for developing drug-like BAG-1 inhibitors and/or testing the efficacy of existing inhibitors of BAG-1 mediated pathways.