SOX2 and glioma: Notably, a previous study demonstrated that melatonin (100 μM) had no effect on the transcription of Sox2 in a proliferating murine embryo stem cell line (38), which suggested that the induced transcription of Sox2 was the result of either a differential response to a higher concentration of melatonin or a specific response of the cancer-derived C6 glioma cell line.