POU5F1 and breast cancer: Multivariate analysis indicated that lymph node metastasis (odds ratio [OR]: 7.645; 95% confidence interval [CI]: 1.974–29.612; p = 0.003) and the molecular type of breast cancer (OR: 14.776; 95% CI: 3.386–64.477; p = 0.001) were independent factors associated with Oct-4 and Nanog co-expression (Table 3).