VCAM1 and neoplasm: Using this imaging agent, subcutaneous MDA-MB-231 tumors were successfully visualized by SPECT/CT imaging, whereas significantly lower signals were found in HCC70 tumors (which do not express hVCAM-1 mRNA and protein) or using the negative irrelevant control sdAb, thereby indicating that the signal was specific and predominantly attributable to tumor cell expressing VCAM-1 rather than murine endothelial or inflammatory cells.