SOX2 and neoplasm: The synergism of PSPC1-Y523F with exogenous or endogenous PTK6 in various tumor-promoting functions was demonstrated in SK-hep1 or SNU-387 cells, respectively, including the increase in EMT morphology, upregulation of the mesenchymal marker N-cadherin, downregulation of the epithelial marker γ-catenin, increased expression and promoter activity of EMT-TFs (Snail and Slug), elevated expression of CSC-TFs (Nanog, Sox-2 and Oct-4) and increased stemness features as evidenced by spheroid formation and side population assays (Fig. 2g–j and Supplementary Fig. 3b–e).