LIF and cholangiocarcinoma: The modulatory effect of the PI3K/AKT pathway on LIF-induced Mcl-1 up-regulation was confirmed by treating CCA cells with LY294002, a specific PI3K inhibitor, which significantly reduced Mcl-1 expression in LIF-stimulated HuCCT-1 and TFK-1 cells (Figure 4C, 4D).