TWIST1 is upregulated and FOXO3a (the forkhead box class O 3a, which belongs to the FOXO subclass of forkhead transcription factors) is downregulated in breast cancer tissues, and overexpression of TWIST1 can reverse the effect of FOXO3a on proliferation, invasion, migration, and EMT. This evidence concerns the gene FOXO3 and breast carcinoma.