FOXO3 and prostate cancer: It has been shown by others in prostate cancer that FOXO3a, another FOXO family member, downregulates β-catenin by transactivating its targeting microRNAs miR-34b/c and inhibits its transcriptional activity by directly binding to β-catenin [37], suggesting that FOXO protein family members may share broad β-catenin inhibitory functionalities in cancer, although their superiority may differ in different cancers.