(A) SCC1 cells were plated in duplicate in 96-well plates. Cells were treated with virus (Ad-TIMP-2 or Ad-TIMP-2 + Ad Wt 300) at 10 or 100 MOI. Cell viability was decreased by 35–45% at 48 h after infection with Ad-TIMP-2 and Ad Wt 300 compared to untreated control cells. (B) SCC1 cells were plated in duplicate in 96-well plates. Cells were treated with Ad-TIMP-2, Ad-TIMP-2 + Ad Wt 300, Cisplatin, or radiation alone or in combination. Treatment with the Ad-TIMP-2, radiation (8 Gy), or Cisplatin alone resulted in 23–30% reduction in cell viability after 48 h. Combination treatment with replicative Ad-TIMP-2, Cisplatin and radiation produced a 67% decrease in cell viability at 48 h. The combination of radiation with Cisplatin increased the cell killing when compared to radiation alone (p=0.025). The triple combination of radiation, cisplatin, and either Ad-TIMP-2 or Ad-TIMP-2 + Ad Wt 300 was the most significant (p=0.001).