In order to investigate the role of a broad range of pro- and anti-inflammatory cytokines in obesity, serum levels of TNF-α, IFN-γ, IL-2, IL-4, IL-5, IL-10, IL-12, IL-13, and GM-CSF were compared between obese and non-obese participants. This evidence concerns the gene IL5 and obesity due to melanocortin 4 receptor deficiency.