ERBB2 and metastatic neoplasm: Other antibodies targeting HER2 are Pertuzumab, a humanized antibody recognizing a different HER2 epitope involved in homo- or heterodimerization [30] which has very recently been approved by FDA in combination with trastuzumab and docetaxel for the treatment of patients with HER2-positive metastatic breast cancer (mBC) who have not received prior anti-HER2 therapy or chemotherapy for metastatic disease; and T-DM1, a drug conjugated version of trastuzumab, which has recently demonstrated superb clinical effects in a controlled Phase II trial conducted in Trastuzumab-resistant patients [31].