CCL2 and obesity due to melanocortin 4 receptor deficiency: In particular, circulating concentrations of C-reactive protein (CRP) and interleukin (IL)-6 have been shown repeatedly to correlate positively with obesity24, , , , –29 in addition to tumour necrosis factor alpha (TNFα),29 monocyte chemoattractant protein 1 (MCP-1/CCL2),30 interleukin-8 (IL-8)30 and soluble intracellular adhesion molecule 1 (ICAM-1).31 This positive correlation between makers of inflammation and adiposity has led to suggestions that obesity is an inflammatory condition.