Fig. 6. Effect of the overexpression of Notch1 or Notch3 intracellular domains on IB expression. Cells were transfected with N3-ICD, N1-ICD or empty (mock) plasmids and treated for 6 hours with IL-1 (10 ng/ml) or vehicle (control). IB transcripts were assayed by RT-PCR. Results are expressed as a percentage of the IB mRNA level from control cells and represent the mean ± s.e.m. of three independent experiments. C, control; IL, IL-1; *, P<0.05; ** P<0.01.