TGFB1 and benign prostatic hyperplasia: Many studies and our previous research have illustrated that the activated epithelial-mesenchymal transition (EMT) process of prostate epithelial cells and the incontrollable growth of prostate stromal cells are essential pathogenesis processes of BPH; in this progression, excessive levels of transforming growth factor-beta 1(TGF-β1) and then activated TGF-β/Smad signaling are important initiators [6–8].