HNF4A and breast cancer: The luciferase-based TOP (harboring the TCF/LEF binding site) reporter assay (used to test the inhibitory effect of BC-23 on the transcriptional activity of Wnt/β-catenin pathway in β-catenin overexpressing cancer cells) revealed that BC-23 dose-dependently inhibited TOP-luciferase activity in H1299 cells, with an IC50 value of 2.3 μM (Fig 2).