As examples, ErbB2/HER2 and sodium iodide symporter (NIS) imaging can be employed to discern the difference or discordance in protein expression (HER2 status, which is used in the clinic to assign therapies such as trastuzumab [13]) and the differential sensitivity to chemotherapy [14], respectively, between primary tumor and the corresponding metastases. This evidence concerns the gene SLC5A5 and neoplasm.