POU5F1 and cancer: Previous studies have shown that CD276 upregulation promotes the expression of stem cell markers, such as Prominin 1 (PROM1/CD133) [30], CD44, and POU Class 5 Homeobox 1 (POU5F1/Oct4), potentially facilitating the epithelial–mesenchymal transition (EMT) in certain cancers [31,32].