FASN and obesity due to melanocortin 4 receptor deficiency: As shown in Figure 1, the mRNA expression of SREBP1 (p = 0.0176), FASN (p = 0.0412), ACACA (p = 0.0255), FTO (p < 0.0001), and ATF4 (p < 0.0001) was significantly reduced in the obesity group compared to the control group.