Induction of FasL and Fas mRNA in CEM cells. Total RNA was isolated from 3 × 10⁵ CEM cells after treatment with 100 μM ara-G at the indicated times. The relative mRNA levels of FasL (A) and Fas (B) were measured by real-time RT-PCR, normalized to the levels of GAPDH mRNA, and expressed as percentage of the levels in untreated cells.