INSR and obesity due to melanocortin 4 receptor deficiency: A recent study showed that the insulin receptor (Insr) in pancreatic acinar cells of KrasG12D is essential for the formation of hyperinsulinemia-driven PanIN under the condition of high-fat-diet-induced obesity, and its loss can inhibit the occurrence of hyperinsulinemia-associated pancreatic cancer, revealing the mechanism of the link between hyperinsulinemia and pancreatic cancer [144].