In the phase II trial carried out by the Children’s Oncology Group, 96 newly diagnosed metastatic osteosarcoma patients (41 with HER2 overexpression shown by IHC) received both standard chemotherapy (a combination of cisplatin, doxorubicin, methotrexate, ifosfamide, and etoposide); trastuzumab (weekly for a total of 34 cycles) was added to the treatment of 34 of the HER2-positive patients. The gene discussed is ERBB2; the disease is osteosarcoma.