Comparison of ICSBP- andbcr-abl-transcript levels in vitro. (A) Mononuclear cells from a patient with CML were incubated for 24 hours with no cytokine (lane 1), IFN-α (lane 2), or IFN-γ (lane 3). In IFN-γ–treated cells ICSBP-mRNA levels increased, but no change was seen with bcr-abl-mRNA levels. (B) Stable transfectans of ICSBP-expressing (lanes 1 through 3) and nonexpressing K-562 cells (lanes 4 through 6) are compared. Incubation for 24 hours with no cytokine (lanes 1 and 4), IFN-α (lanes 2 and 5), or IFN-γ (lanes 3 and 6) showed no differences inbcr-abl-mRNA levels. Experiments were performed with three different transfected clones each and the mean is displayed (±SEM).