The advantages of recombinant viruses for cancer therapy include (i) specific engineering for infection, replication and killing of tumor cells [1], (ii) amplification of the therapy itself by the tumor, (iii) stimulation of an anti-tumor immune response by breakdown of tumor immune tolerance [3], (iv) a bystander effect especially if the virus is armed with specific genes such as the sodium iodide symporter (NIS) [4]. The gene discussed is SLC5A5; the disease is infection.