RSPO3 and obesity due to melanocortin 4 receptor deficiency: On the contrary, as observed in the setting of obesity, decreases in hepatic Rspo3 expression and its function contribute to reducing the stimulation signal delivered to WAT-derived thermogenesis, resulting in WAT enlargement, while it contributes to producing that delivered to BAT-derived adaptive thermogenesis against obesity development, a phenomenon which precisely reflects the pathophysiology of obesity.