SOX4 also plays pivotal roles in cancer development; it aberrantly upregulates in various types of cancer, including breast cancer [7], lung cancer [8, 9] as well as cervical cancer [10] and induces epithelial-to-mesenchymal transition (EMT), by activating TGF-β pathway in breast and gastric cancers and/or by PTEN ablation in prostate cancer [11–13]. Here, SOX4 is linked to breast cancer.