Figure 1From: Transforming growth factor-β and breast cancer: Transforming growth factor-β/SMAD signaling defects and cancerThis model schematically illustrates the various molecular mechanisms that can contribute to negative regulation of SMAD signaling and thereby to a loss of transforming growth factor (TGF)β-induced growth inhibition. Inactivating mutations or loss of expression of components of the TGFβ/SMAD signaling pathway are not depicted here but may also be important. For details, see text.Back to article page