CRF induced the expression of β-catenin and SMAD2. Western blot analysis were performed as described in Materials and methods in order to asses the effect of CRF on β-catenin and SMAD2 expression at protein levels. CRF significantly induced the expression of β-catenin (A,B) at 4 and 6 h whereas the expression of SMAD2 (A, C) was significantly induced at 6, and 24 h. Data are expressed as MEAN ± SEM of five independent experiments. * p < 0.05 compared to untreated control. D. 4T1 cells were transfected with a luciferase construct containing a WNT-responsive element in which the complex of β-catenin and Tcf binds. Cells were stimulated with CRF and luciferase activity was measured in cell lysates 24 hours following stimulation. Data are expressed as MEAN ± SEM of three independent experiments (*p < 0.05). E. 4T1 cells were stimulated with TGFβ at 5 ng/ml in the presence or absence of CRF at 10-8M and proliferation was measured using the MTT assay. Data are expressed as MEAN ± SEM of three independent experiments. * p < 0.05 compared to TGFβ -only treated cells.