High expression of MST4 was detected in 102 cases of 105 adjacent noncancer liver tissues (97.1%), and that of MST4 in HCC tissues was 36.2% (38 cases) (Fig. 1D, E, Table S1), indicating that MST4 is frequently downregulated in human HCC clinical specimens. This evidence concerns the gene STK26 and hepatocellular carcinoma.