2. If the patient participating on the study has an easily accessible breast mass or metastatic lesion (e.g. lymphadenopathy, skin metastasis, chest wall metastasis), a core needle or punch biopsy will be obtained at study entry (prior to starting study medications), four weeks after starting study medications, and at disease progression. These biopsies will be strongly encouraged but the patients may decline any or all of them without impacting their eligibility or continuation on the study.