siRNA against Hes-6 causes a reduction of E2F-1 mRNA. Relative Hes-6 (a) and E2F-1 mRNA levels (b) in MCF-7 cells transfected with 50 nM siRNA against Hes-6 (siRNA-Hes-6) or luciferase as control (control). Graphs are presented as values relative to MCF-7 cells transfected with the siRNA luciferase control vector. All bars represent mean values ± SD of three samples, and experiments were repeated twice with similar results. Significance is presented as *P < 0.05.