(A) Cell number (•) and viability (○) of U-266-1984 cells incubated with IFN-γ at increasing concentrations (0 to 1,000 U/mL). Cells were harvested at 96 hours and the number of viable cells was determined by using trypan blue exclusion. (B) Cell number (•) and viability (○) of U-266-1984 cells incubated with IFN- at increasing concentrations (0 to 1,000 U/mL). Cells were harvested at 96 hours and the number of viable cells was determined by using trypan blue exclusion.