OTC and fibrosis: Previous studies have shown that even the early stage of NAFLD development (prior to the development of fibrosis and cirrhosis) is associated with reduced capacity of the liver for urea synthesis, with decreased expression and function of the enzymes involved in the urea cycle, including carbamoyl phosphate synthetase I (CPS1) and ornithine transcarbamylase (OTC) [15,16,17].