SERPINF1 and obesity due to melanocortin 4 receptor deficiency: We have previously shown that although circulating PEDF levels are a marker of insulin resistance in both animal models and humans26,29, PEDF addition improves hepatic insulin resistance in vitro and ameliorates metabolic derangements in an animal model of T2DM with obesity and insulin resistance30,31, thus suggesting that serum PEDF levels are increased as a counter-system against insulin resistance as well.