TGFB1 and hepatocellular carcinoma: On the other hand, HepG2 cells did not acquire higher invasive capacity when β3 was overexpressed in the cells only by transfection with β3 expression vector (data not shown), indicating that β3 alone could not increase the invasive capacity of non-metastatic HCC cells without the stimulation with TGF-β1/H2O2/HOCl.