Sensitivity of multiple cell lines to conditional Fas, caspase-1, and caspase-3. Jurkat-Tag, 293, and HeLa cells were transiently transfected with a constitutively expressing luciferase reporter plasmid and control vector MFv2 (shaded bars), MFv2-Fas plasmid (wide cross-hatched bars), control vector Fpk3 (narrow cross-hatched bars), Fpk3-casp-1 (bricked bars), or Fv2-casp-3 (solid bars). After 24 h, transfected cells were split into duplicate cultures and 500 nM drug (AP1903 for Fv or FK1012 for Fpk) was added to one culture for an additional 24 h. The percent relative reporter activity is the percent of luciferase activity after drug addition relative to untreated cells. Error bars represent the SD of the mean activity of three transfections.