RXRA and obesity due to melanocortin 4 receptor deficiency: Furthermore, to assess the effect of obesity-associated insulin resistance on RXRα S22 phosphorylation in BAT, we measured RXRα S22 phosphorylation in BAT from either lean mice fed with control diet (CD) or diet-induced obese and hyperglycaemic mice fed a high-fat diet (HFD) for 8 weeks (Supplementary Figure 1(d)).