With respect to the high incidence of CRC as third most common cancer worldwide [2], which lacks new therapeutic options with clinical benefits, improved response and survival, especially for metastatic CRC where only a low percentage of patients are eligible for surgery, we established an in vivo metastases colon cancer model to investigate the NIS gene therapy concept as a new treatment option for CRC metastases. This evidence concerns the gene SLC5A5 and colorectal carcinoma.