EGFR and breast cancer: Thus far, several targeted agents such as inhibitors for poly(ADP-ribose) polymerase, vascular endothelial growth factor receptors, epidermal growth factor receptors, ras/raf/mitogen activated protein kinase, phosphatidylinositol 3-kinase, IGF 1, histone deacetylase, and heat shock protein 90, are being explored as potential therapeutic targets for breast cancer, with many of them in clinical trials [9,55].