Fig. 5. Smad3 inhibits CBFA1 function and mediates the inhibitory effect of TGF-β (1 ng/ml). Cells were transiently transfected with expression plasmids and luciferase reporter plasmids, as shown. Luciferase expression from the reporter plasmids was scored as in Figure 2. (A, D and F) 10T1/2 cells, (B) Smad2^–/– mouse embryonic fibroblasts, (C) Smad3^–/– mouse embryonic fibroblasts, (E and F) ROS 17/2.8 cells.