TNF and obesity due to melanocortin 4 receptor deficiency: Obesity is associated with enhanced adipocyte death and infiltration of macrophages into white adipose tissue.5, 6 Many inflammation-provoking 'adipokines', such as PAI-1 (plasminogen activator-1) and MCP-1 (monocyte chemoattractant protein-1), and macrophage-specific genes, including tumor necrosis factor-α and interleukin-6, are significantly upregulated in the white adipose tissue of obese subjects.7, 8 Within liver tissue, obesity and inflammation are linked by activation of the nuclear factor-κB (NF-κB) transcription factor.