(K) Inhibitory effect of SMAD3i (SIS3) on the SMAD-responsive luciferase activity. Vector encodes the Firefly luciferase reporter gene under the control of a minimal (m)CMV promoter and tandem repeats of the SMAD Binding Element (SBE). Cells (10,000 per well) were pretreated with SMAD3i 10µM or control solvent during 1.5hr, and next cells were exposed to TGFβ 10ng/mL (or solvent: HCl 4mM + Bovine serum albumin 1mg/mL) for 6hr. n=3 biologically independent experiments. Each histogram represents the mean + s.d. ; 