IGFBP2 and obesity due to melanocortin 4 receptor deficiency: Overexpression of IGFBP2 reduced the predisposition to obesity and improved insulin resistance under normal and high-fat diet in transgenic mouse models such as the ob/ob mouse or diet-induced obesity models [26,28], supporting a rather systemic impact of IGFBP2 in metabolic diseases including obesity and NAFLD.