STAT3 and obesity due to melanocortin 4 receptor deficiency: Obesity is characterized by chronic low-grade inflammation, marked by increased proinflammatory cytokines and decreased anti-inflammatory adipokines, which activate key pathways such as Nuclear Factor kappa-light-chain-enhancer of activated B cells (NF-κB), Signal Transducer and Activator of Transcription 3 (STAT3), and Activator Protein 1 (AP-1).