As shown in Fig. 7a, SOX2 expression level significantly converts poor prognosis (Chisquare p-value = 0.014, Logrank p-value = 0.02268), and the distant metastasis-free survival of breast cancer patients expressing high, middle and low levels of SOX2 protein were 50.4, 70.5 and 78.6%, suggesting that high levels of SOX2 are correlated with poor prognosis in breast cancer patients. The gene discussed is SOX2; the disease is breast cancer.