TGFB1 and prostate cancer: Studies have demonstrated that loss of the TGF-β/Smad signaling function including defects in TGF-β receptors and/or downstream signal molecular Smad proteins is associated with tumor progression, and specific defects in this signalling pathway has been found in many cancers, including pancreatic, breast, ovarian, colorectal, liver, prostate cancer, leukemia, etc. [24-30].