MTOR and hepatocellular carcinoma: To study the role of mTOR in 5-Fu induced apoptosis of HCC cells, SMMC-7721 cells were treated with or without 5-Fu at the concentration of 62.5 μg/ml for 36 h, and then cell lysates were prepared, and Western analyses were performed with an antibody specific for the phosphotylated form of p70s6 kinase at Thr389, the position known to be phosphotylated by mTOR.