In addition to the primarytumor site, we also detected unexpected fluorescence in the spleenthat was suspected to be metastatic disease based on prior reportswith this animal model.37,38 Analysis of tumor andsuspicious lesions confirmed cancer status (H&E) and SSTR2-positiveregions (IHC) that correlated with fluorescence (Figure 5F). Here, SSTR2 is linked to metastatic neoplasm.