Hepatic SCD has been associated with fatty liver, obesity, and metabolic diseases [42]; here we found mRNA level of scd was upregulated by over feeding and high-fat diet in WT, HBx(p53-) and Src(p53-) fish, which might indicates high hepatic scd plays a direct role in the development of fatty liver and development of metabolic disorders. Here, SCD is linked to obesity due to melanocortin 4 receptor deficiency.