Cytosolic β-catenin protein levels and β-catenin/TCF-dependent transcriptional activity were found to be downregulated following the treatment with the two Pygo2 shRNAs in the lung cancer cell lines examined (Fig. 2A and B), indicating that Pygo2 functions as a positive regulator of the canonical Wnt/β-catenin signaling pathway in these cells. This evidence concerns the gene HNF4A and lung cancer.