POU5F1 and neoplasm: Exosomes released from tumor cells and stromal cells effectively promote CSCs to remain stem and tumorigenic (129): some tumor-derived exosomes are able to carry stem cell-related genes, such as OCT-4, SOX-2, NOTCH1, and NANOG, or promote their expression by mediating lncRNA/microRNA to enhance the stem cellularity of CSCs and maintain tumor heterogeneity (130).