The influence of Ad/TRAIL-F/RGD on radiosensitivity was examined on the basis of the clonogenic survival of cell lines after exposure to PBS, Ad/CMV-GFP (GFP), Ad/TRAIL-F/RGD (TRAIL), radiation (RAD), Ad/CMV-GFP plus radiotherapy (GFP+RAD), Ad/TRAIL-F/RGD and radiotherapy (TRAIL+RAD). The MOIs for the cells were 500 VP for Seg-1 cells and 5,000 VP for SKGT-5 cells. Each experiment was performed in triplicate and repeated at least twice. Values are means of the results of triplicate assays. Bars, standard deviation. P<0.05 in Figure 5 as comparison between Ad/TRAIL-F/RGD plus radiation and PBS, Ad/CMV-GFP, Ad/TRAIL-F/RGD, radiation, Ad/CMV-GFP plus radiation respectively and combined.