ERBB2 and neoplasm: To examine the in vivo tumor accumulation of αHER2/SPIO in HER2-positive tumors by MR imaging, αHER2/SPIO or αDNS/SPIO were intravenously injected into mice bearing subcutaneous MCF7/HER2(HER2++) tumors and MCF7/HER2(HER2+/−).