Specific downregulation of DREAM mRNA expression. (a) The effect of five different small interfering RNAs (siRNAs) tested. All show an overall reduction in DREAM expression of 70% to 90% compared with the expression in mock-transfected cells and cells transfected with siRNA-green fluorescence protein (100%). (b) Time course of reduced levels of DREAM expression in synovial fibroblast-like cells transfected with siRNA3 and siRNA4 and incubated 24, 48, and 72 hours. DREAM, downstream regulatory element antagonist modulator.