TCF4 and colorectal cancer: Destruxin B, a cyclodepsipeptide from the entomopathogenic fungus Metarhizium anisopliae, suppressed proliferation and induced cell cycle arrest in human colorectal cancer HT29, SW480 and HCT116 cells suppressing Wnt-signaling by the downregulation of β-catenin and TCF4 protein levels and β-catenin/TCF4 transcriptional activity measured in the TOPFlash assay, concomitantly with decreased expression of the target genes cyclin D, c-myc and survivin.