To this purpose, BSEP KO mice were challenged with MCD diet to induce steatohepatitis, a model which has been used previously by others to induce profound steatosis and inflammation and some degree of fibrosis in rodents,41, 42, 43, 44, 45 although several short comings such as weight loss, lack of insulin resistance and obesity in this model need to be acknowledged.46, 47. This evidence concerns the gene ABCB11 and obesity due to melanocortin 4 receptor deficiency.