Total RNA (1 μg) was reverse-transcribed using Superscript III and oligo (dT) and analyzed for Casp9, Bcl-x, caspase 8, and caspase 2 splice variants as previously described(17 ). Real-time: Total RNA was used for real-time PCR for Casp9a, Casp9b and 18s using TaqMan PCR master mix and the Applied Biosystems 7500 Real-Time PCR System. Casp9a and 18s Q-PCR primers were ID numbers Hs00154261_m1 and Hs99999901_s1. The Q-PCR primers for Casp9b were 5′-TTTGGTGATGTCGGAGCAGA-3′ (forward) and 5′-GATTTGGTGATGTCGGAGCA-3′ (reverse) and 5′-TTCCCCTGAAGACGAGTCCCCTGG-3′ (probe).