However, no consistent upregulation of mTOR signaling, as revealed by phosphorylated/activated (p)-mTOR, (p)-RPS6, and (p)-4EBP1 expression was detected, suggesting that elevated levels of the AKT cascade do not always lead to upregulation of mTOR signaling in U0126-treated human CCA cell lines. This evidence concerns the gene RPS6 and cholangiocarcinoma.