NR3C2 and obesity due to melanocortin 4 receptor deficiency: In another study by Lefranc et al., the authors investigated the MR-mediated regulation of mitochondrial respiration in adipose tissue both in vivo and in vitro, demonstrating that MR activation increases the production of ROS and causes mitochondrial dysfunction, whereas treatment with MRAs improves obesity-related oxidative stress and prevents cell senescence.