An EGFR and HER2 inhibitor (IC50s 13 and 38 nM respectively) selectively inhibits the proliferation of HER2 BT474 and SKOV3 cells (IC50s 5.1 and 43 nM respectively) over HER2- MDA-MB-231 cells (IC50 3500 nM) decreases tumor growth without affecting body weight in BT474 and SKOV3 mouse xenograft models at 10 mg/kg per day