It has been reported that SOX4 protein upregulated and exerted an oncogenic function in cancers of prostate cancer,9 endometrial cancer10 and breast cancer.11 In breast cancer, high expression of SOX4 induces epithelial–mesenchymal transition and results in a cancer stem cell-like phenotype in breast cancer cells.11 However, a reduced expression of SOX4 was detected in cancer of cutaneous melanoma,12 primary gallbladder carcinoma13 and colon cancer,14 and SOX4 has a cancer suppressor gene role. The gene discussed is SOX4; the disease is breast cancer.