RARRES2 and obesity due to melanocortin 4 receptor deficiency: The novelty of this current study lies in the finding that RvE1 and Chemerin regulate the progress of beige fat and influence metabolic homeostasis subsequently, implying that the Chemerin/RvE1-CMKLR1-mTORC1 signaling pathway may reveal a potential therapeutic target against obesity and the related metabolic disorders.