 HER1 is expressed or over-expressed in many human solid tumors and plays an important role in progression to invasion and metastases.. The association between HER2 overexpression and poor prognosis in node-positive and advanced breast cancer has been shown by a number of studies. Based on this association between the members of HER1HER2 family and worse clinical outcome, antibodies and small molecules that specifically target these receptor tyrosine kinases were developed for their therapeutic efficacy. 