Studies have also shown that adenoviral constructs containing NIS used to transfect prostate cancer xenografts demonstrated uptake of radioiodine sufficient to induce tumor volume reduction up to 80% in comparison to control tumors after treatment with a single dose of 131I (Spitzweg et al., 2001; Kakinuma et al., 2003). The gene discussed is SLC5A5; the disease is prostate carcinoma.