ERBB2 and breast cancer: F. leucopyrus decoction is significantly cytotoxic to all three breast cancer cell phenotypes used in this study (MCF-7, MDA-MB-231 and SKBR-3) with greater cytotoxicity being exerted in Her2 negative phenotypes MDA-MB-231 and MCF-7 than in the Her2 positive phenotype SKBR-3.