The POU class 5 homeobox 1 (POU5F1) gene, a transcription factor involved in the self-renewal of undifferentiated stem cells and induction of embryonic pluripotency via metabolic mechanisms, has been shown to be involved in β-cell dedifferentiation in type 2 diabetes [31] and is altered in breast cancer [32]. This evidence concerns the gene POU5F1 and type 2 diabetes mellitus.