SMAD3 and hepatocellular carcinoma: In this study, Western blotting analyses showed that 10 ng/mL TGF-β1 strongly increased the phosphorylation of Smad2, Smad3, Akt, mTOR, and P70S6K (downstream of mTOR) in HCC cells, whereas total Smad2/3, Akt, mTOR, and P70S6K levels were unchanged.