CCKAR and obesity due to melanocortin 4 receptor deficiency: A challenge in developing effective CCK1R agonists for the treatment of obesity has been side effects of highly potent and/or long-acting full agonists that can cause nausea, abdominal cramping, and diarrhea, with the theoretical possibility observed in rodents of trophic effects on receptor-bearing cells and the possible progression and/or development of pancreatic cancer (11).