ERBB2 and breast cancer: Given that ganetespib was well-tolerated in ErbB2+ breast cancer patients38 and that lapatinib, a dual inhibitor of EGFR and ErbB2, has been approved for the clinical treatment of metastatic ErbB2+ breast cancer49, we extended our study to examine whether ganetespib can enhance lapatinib-mediated inhibition of ErbB2+ breast cancer cells.