POU5F1 and cancer: Lactate conversion into pyruvate in tumoral cells supplies mitochondrial oxidative phosphorylation, serving as an energy source but also as a metabolite that can influence upstream signal activation directly or indirectly through ROS generation, histone lactylation and histone acetylation that could regulate expression of pluripotent genes such as Oct4, Sox2, c-Myc, and also could improve CD133 transcription and acquisition of cancer-stem like features [43].