POU5F1 and neoplasm: For example, in breast cancer, abnormal activation of Notch1 suppresses the expression of differentiation-related genes (such as GATA3) and drives the upregulation of stem cell-related genes (such as SOX2 and OCT4), This sustains the undifferentiated state of tumor cells, enhances their proliferative capacity, and increasing drug resistance (28, 29).