TGFB1 and hepatocellular carcinoma: Some cell lines (HCC-M, HCC-T, PLC, Hep3B, HuH7) exhibited a prolonged pSmad2 signal after continuous stimulation with TGF-β up to 48h, whereas others (HepG2, HLE, HLF) faded out after 1-7h of TGF-β treatment.