KDM1A and obesity due to melanocortin 4 receptor deficiency: From the published mechanisms of epigenetic modulations under obesity or diabetic condition [13,28,31], and involved in target genes regulation including inflammatory factors [32,33,34], we noted that epigenetic H3K4me and H3K9me modifications were highly associated with metabolic obesity as well as diabetic complications; therefore, we speculate that Set7 (H3K4 methyltransferase), Suv39, or LSD1 (H3K9 methyltransferase) might be key regulatory factors in 12/15-LO triggered histone methylation around inflammatory gene promoters.