SOX9 and liver cancer: Then, the expression of stem cell surface markers (SOX9 and OCT4) was assessed in Gadd45β transfected SMMC-7721 and Hep-3B cells, the results showed that SOX9 and OCT4 expression were reduced at both mRNA and protein levels in Gadd45β transfected liver cancer cells (*P < 0.05; **P < 0.01; ***P < 0.001) (Fig. 2d, e, f).