TNF and obesity due to melanocortin 4 receptor deficiency: Obesity is a chronic low-grade inflammatory condition characterised by the up-regulation of pro-inflammatory cytokines (e.g., TNF-α, IL-6, IL-1β, MCP-1) and free fatty acids in the circulation, as well as the activation of inflammatory pathways (e.g., P38/JNK MAPK pathways), which contribute to kidney hypertrophy and dysfunction.