ERBB2 and breast carcinoma: In vivo, pazopanib prevented experimental brain metastases by 231-BR cells or HER2 transfectants of MCF7 breast carcinoma cells (selected for brain tropism, (MCF7-HER2-BR3)) by 73% and 55%, respectively; a concomitant reduction in pERK activity was observed, suggesting that B-Raf was a drug target in vivo.