Overexpression of DN-Tcf4 in induced HCT-116 cells. A stably transfected clone of HCT-116 cells was treated with 4 μg/ml doxycycline (Doxy) and/or 5 mM NaB for 17.5 hr or left untreated. Protein was isolated, and DN-Tcf4 detected with anti-FLAG antibody in western blot analysis. Actin was analyzed as a control. Duplicate samples from a representative western blot shown.