LEP and obesity due to melanocortin 4 receptor deficiency: Notably, a high level of inflammation mediators was observed in solid tissue and cyst fluid in patients with CP, and two independent studies reported that injection of cyst fluid into the cortex of rat or the hypothalamus of mice increased body weight [34,35]; thus, the inflammation mediators secreted from the tumor may play an essential role in leptin resistance and development of obesity, and more studies are needed to reveal the mechanisms.