Obesity is associated with increased systemic inflammation, and in fact, lean mice have been found to have more CD4+ T cells, which are essential for the suppression of pro-inflammatory macrophages, unlike obese mice, in which CD8+ T cells have been shown to play a role in the recruitment and activation of pro-inflammatory macrophages [36]. The gene discussed is CD8A; the disease is obesity due to melanocortin 4 receptor deficiency.