INSR and obesity due to melanocortin 4 receptor deficiency: Notably, bilirubin treatment of a diet-induced model of obesity in mice reduced body weight and mitigated elevated blood glucose, total cholesterol (TC), leptin, and adiponectin levels, as well as normalized transcripts of sterol regulatory element-binding protein (SREBP-1), insulin receptor (IR), and PPARγ, and improved insulin sensitivity [79].