IL6 and obesity due to melanocortin 4 receptor deficiency: This inflammation is characterized by increased serum concentrations of C-reactive protein (CRP) [217], interleukin 6 (IL-6), IL-8, monocyte chemotactic protein-1 (MCP-1), and tumor necrosis factor alpha (TNFα) in patients and different animal models of obesity [216, 269–271].