<qa>  What is the expression of amphiregulin?II. To investigate treatment resistance e.g., expression of amphiregulin, epidermal growth factor receptor EGFR, using molecular and immunohistochemical analyses of blood and tumor samples of pre- and post- when available treatment tissues. Microarray analyses to quantitate the expression of specific estrogen-responsive genes e.g. thyroid transcription factor 1 TTF1 and PDZK1 will also be performed. 