Fig. 7. Model of Smad/ß-catenin signaling in normal and dysplastic renal tissues. In the absence of Bmp-stimulated Smad1/ß-catenin interactions, Myc expression is inhibited by Smad1 bound to Smad-binding regions. By contrast, in dysplastic tissue, formation of Smad1/ß-catenin/Tcf4 molecular complexes stimulates Myc transcription via mechanisms to be defined.