Ad-PTEN, but not Ad-Luc, causes cell death in melanoma cells. Increasing doses of viruses (0),1000,2500,5000,7500, and 10,000 vp/cell) were used to treat cells and cells were harvested 3 days after infection, treated with Trypan blue and counted. The percentage of dead cells is displayed on the y axis. (A) WM35 cells. (B) A375-S2 cells. (C) MeWo cells. (D) NHEM cells. All graphs are the average of three experiments, except that of NHEM, which is the average of two experiments. The error bars represent the standard error of the mean.