The initial event in obesity-induced systemic inflammation is the secretion of specific chemokines such as C-C motif chemokine ligand 2 (CCL2) and leukotriene B4 (LTB4) from adipocytes which promote monocyte trafficking into the adipose tissue (26, 31). This evidence concerns the gene CCL2 and obesity due to melanocortin 4 receptor deficiency.