ERBB2 and breast carcinoma: The receptor tyrosine kinase ErbB2 (Her2/Neu) is overexpressed in 20% of breast cancers [1]; epidermal growth factor receptor (EGFR) is highly expressed in non-small-cell lung cancers [2]; and the FLT3 receptor is mutated in 30% of acute myelogenous leukemias (AML) and other hematological malignancies [3].