SMUG1 and neoplasm: As expected, the tumor volume and FDG uptake signal were significantly decreased in the Ad-EC, CDDP, Ad-EC+CDDP and Cetuximab treated groups at 30th days compared with the PBS and Ad-GFP treated control groups; especially in the Ad-EC+CDDP combination group, tumor tissue FDG uptake was as low as normal tissues, indicating that tumor metabolism was significantly inhibited (Fig 4F).