Sine oculis homeobox 1 (SIX1) is a member of homeobox transcription factor family playing critical roles in organogenesis and cancer development and progression.13–16 Overexpression (OE) of SIX1 has been observed in many human cancers, including breast cancer and liver cancer, and is associated with poor clinical outcomes in cancer patients. This evidence concerns the gene SIX1 and breast cancer.