The dual mechanism of NIS has been investigated in several nonthyroidal tumor models [3, 11–17, 19–21, 25, 30–34] and the concept of NIS gene therapy is currently under clinical evaluation for local treatment of prostate cancer after intratumoral application of adenoviral NIS gene carriers (NCT00788307, NCT01846091, NCT02068794) [32, 35]. Here, SLC5A5 is linked to prostate cancer.