TGFB1 and breast cancer: We believe that the natural compound emodin has intrinsic advantages compared to those specific TGF-β1 signaling inhibitors in that 1) with the relatively mild nature of its TGF-β1 signaling inhibition, emodin may only suppress excessive TGF-β1 signaling in the tumors while sparing its physiological activities; and 2) in addition to suppression of TGF-β1 signaling, emodin also acts on macrophage-breast cancer cell interactions through other mechanisms as we showed previously 16, 17.