In this study, GL261 tumor bearing C57BL6/j mice received 5 × 105 syngeneic eGFP-fLuc-HSV-TK-expressing and ihSPIO-labeled (1 % or 10 %) mOct4− BM-MAPCs for longitudinal follow-up of suicide gene therapy in immunocompetent animals following in vitro and in vivo feasibility studies for cell detection. This evidence concerns the gene TKT and neoplasm.