FGF21 and obesity due to melanocortin 4 receptor deficiency: Since obesity or metabolic stress can affect diverse aspects of autophagy or lysosomal function (18–21) and cancer tissue could be deficient in autophagy (4, 6–9, 22), FGF21 produced by autophagy-deficient hepatocytes due to genetic or metabolic causes may affect the behavior of hepatoma with autophagy insufficiency.