TGFB1 and hepatocellular carcinoma: Previous experiments have reported that PDCD4 over-expression induced by transforming growth factor-β1 (TGF-β1) led to Huh7 hepatoma cell apoptosis by activating Bax, releasing cytochrome c from the mitochondria and activating caspase 9, caspase 8 and caspase 3; this also occurred in cells transfected with PDCD4-plasmids (6).