Although the transcriptional regulation of CYP2E1 has been linked to the activities of HNF1α [158], HNF4α [108], SP1 [159], and C/EBP [154], the mechanisms by which obesity and NAFLD exacerbate CYP2E1 activity requires additional studies [153]. Here, CYP2E1 is linked to obesity due to melanocortin 4 receptor deficiency.