FABP4 and obesity due to melanocortin 4 receptor deficiency: Importantly, we demonstrated that upregulation of fatty acid-binding protein 4 (FABP4) by environmental stimuli (i.e., high-fat diet, obesity) upregulates DNMT1, but not DNMT3a and DNMT3b, partially through activation of the IL–6/STAT3 signaling in cell non-autonomous manner in leukemia cells [112].