EGFR and breast cancer: Different types of RTKs are over-expressed in various human malignancies, including breast cancer, they are namely epidermal growth factor receptors (EGFRs), platelet-derived growth factor receptors (PDGFRs), vascular endothelial growth factor receptors (VEGFRs), fibroblast growth factor receptors (FGFRs) and insulin-like growth factor receptors (IGFRs)3,6–8.