Epidermal growth factor receptor (EGFR) is a 170 kDatransmembrane glycoprotein receptor tyrosine kinase that, activated by epidermal growth factor (EGF), affects cell growth and differentiation. Binding of EGF or TGF alpha to EGFR activates tyrosine kinase activity of the receptor. Phosphorylation of Tyr 992, Tyr 1068 and Tyr 1086 is required for conformational change in the C-terminal of EGFR. Autophosphorylation of Tyr 992 creates a binding site for the phospholipase C-gamma (PLC-gamma) SH2 domain, inducing downstream signaling. In breast cancer, EGFR is predominately expressed in basal cell-like carcinoma, it has been recommended for identification of basal-like breast carcinoma along with Cytokeratin 5/6.