Effects of IFNγ on caspase mRNAs. Day-5 cells were incubated for 72 hours with or without 500 U/mL of IFNγ, and RNase protection assays were performed for members of the caspase family. Two separate experiments were performed (lanes 1/2 and lanes 3/4). Twenty-six micrograms of total RNA from each cell group was analyzed with the hApo-1 Multi-Probe Template Set (Pharmingen) to detect caspases-1, -2, -5, -6, -7, -8, and -9 and granzyme B mRNAs.