To that end, we implanted the indicator U251-U3-mCherry-U3-luciferase cells subcutaneously in CB17 SCID mice and upon tumor establishment we infected them intratumorally with 5 doses of 2 * 106 IU of oFV-TK, oFV-iCasp9 or PBS control. Here, TKT is linked to neoplasm.