IGF1 and obesity due to melanocortin 4 receptor deficiency: KrasG12D/+ expressing mice fed a high fat, high-calorie diet developed early pancreatic neoplasia with signs of obesity, hyperinsulinemia, hyperglycemia, hyperleptinemia, hyperlipidemia, and high levels of IGF1, resulting in significant activation of pancreatic stellate cells, recruitment of inflammatory cells, and ECM remodeling [51].