CCL2 and obesity due to melanocortin 4 receptor deficiency: During the development of obesity, progressive hypertrophy of adipocytes promotes tissue hypoxia and macrophages infiltration, which induce the increased secretion of various proinflammatory mediators, such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL −6), plasminogen inhibitor 1 (PAI-1), C-reactive protein (CRP), and monocyte chemoattractant protein 1 (MCP-1), among others, besides the decrease in the concentration of anti-inflammatory adipokines, such as adiponectin, characterizing a chronic inflammation of low grade 6 [98].