FAS and obesity due to melanocortin 4 receptor deficiency: In this study, down-regulation of gene expression of PPARγ, C/EBPα, SREBP-1c, aP2, FAS, LPL, and leptin in 3T3-L1 adipocytes by 18KHT01 (Figure 3) suggested the potential effect of 18KHT01 on preventing adipogenesis, so prevent obesity.