To date, research on FGF21 has focused primarily on its beneficial functions in metabolic disorders such as obesity, type 2 diabetes, and non-alcoholic- or metabolic dysfunction-associated steatohepatitis by reducing fat mass, hyperglycemia, and dyslipidemia (Tillman and Rolph, 2020). This evidence concerns the gene FGF21 and obesity due to melanocortin 4 receptor deficiency.