SUV39H1 and obesity due to melanocortin 4 receptor deficiency: Obesity-induced epigenetic alterations mediated by the methyltransferase SUV39H1, the demethylase JMJD2C, and the acetyltransferase SRC-1 decrease H3K9me2/me3 and increase H3K9 acetylation (H3K9ac), which bind to the p66Shc promoter, causing mitochondrial ROS overproduction in visceral fat arteries (VFAs) from obese subjects compared to nonobese subjects [34].