With respect to the co-expression patterns of POU5F1P1/POU5F1P3, POU5F1P1/POU5F1P4, and POU5F1P3/POU5F1P4 in breast cancer tissue, the survival probability was significantly poor in the low/low group of POU5F1P3/POU5F1P4, whereas the other co-occurrence groups showed non-significant survival probabilities (Supplementary Fig. S4a). This evidence concerns the gene POU5F1P4 and breast cancer.