UCP2 and obesity due to melanocortin 4 receptor deficiency: The anti-obesity mechanism of PCHP involved significantly downregulating fatty acid synthase (FAS), sterol regulatory element-binding protein-1c (SREBP-1c), peroxisome proliferator-activated receptor-γ (PPARγ), and CCAAT/enhancer-binding protein-α (C/EBPα) gene expression, while increasing levels of carnitine palmitoyltransferase 1 (CPT1) and uncoupling protein 2 (UCP2), which are strongly associated with glucolipid metabolism and thermogenesis (Liang et al., 2021).