STK26 and hepatocellular carcinoma: In order to confirm the function of PI3K/AKT pathway in the inhibitory effect of MST4 on the proliferation of HCC cells, we inactivated MST4 in HCC cells by ectopic expression of a dominant-negative mutant of MST4 protein and intervened PI3K/AKT pathway with PI3K inhibitor LY294002.