POU5F1 and breast cancer: To further validate that hyperglycemia may increase stemness in breast cancer cells, we cultured MDA-MB-231-LM2 cells carrying a reporter construct in which 6 concatenated repeats of a composite SOX2/OCT4 response element from the proximal human NANOG promoter are coupled to a minimal cytomegalovirus (CMV) promoter, to drive expression of a fluorescent reporter gene for stem cell signaling (37).