HCRT and obesity due to melanocortin 4 receptor deficiency: The role of orexin in non-alcoholic steatohepatitis (NASH) development has been studied by Tsuneki et al; they observed a severe obesity, with NASH and fibrosis progression, in orexin-deficient mice; additionally, when mice were long-term fed with HFD, they showed a progression to hepatocellular carcinoma (HCC).