By enhancing FGF21 expression, MB109 (a recombinant derivative of human BMP9) effectively reduces obesity-induced liver pathologies, including inhibiting lipid accumulation in the liver and significantly decreasing serum levels of alanine aminotransferase (ALT), aspartate transaminase (AST), and total cholesterol. This evidence concerns the gene GDF2 and obesity due to melanocortin 4 receptor deficiency.