PCSK9 and obesity due to melanocortin 4 receptor deficiency: This was achieved through improvements in metabolic parameters, including CD36/liver X receptor α (LXRα)/sterol regulatory element-binding protein 1c (SREBP1c), proprotein convertase subtilsin/kexin type 9 (PCSK-9), and HMGCR, ultimately ameliorating HFD-induced hypercholesterolemia and obesity.