Systemic low-grade inflammation may be a contributing factor for the lower levels of Tregs in obesity, however, it is interesting to note that leptin has been shown to induce proinflammatory cytokines and inhibit Tregs in leptin/leptin receptor – sufficient mice fed high-fat diet (Matarese et al., 2010; Procaccini et al., 2010). This evidence concerns the gene LEP and obesity due to melanocortin 4 receptor deficiency.