Nuclear β-catenin is requirement in the regulation of Nanog. A549 cells and H23 cells infected with control shRNA lentivirus(Cont) or β-catenin shRNA(sh). In both cell lines, β-catenin protein was markedly knocked down with β-catenin shRNA. Knockdown of β-catenin also decreased the Nanog expression. All experiments were carried 3 times independently (Figure 5A). Nanog expression in the A549 and H23 cells with knockdown of β-catenin can not be obviously enhanced by adding EGF, but on the other hand, when the expression of β-catenin is increased by adding EGF, Nanog thereupon increased expression upon β-catenin (Figure 5B). Nuclear β-catenin(Nucles) rather than cytoplasm β-catenin(Cyto) expression in the A549 and H23 cells can be enhanced by adding EGF (Figure 5C).