The decrease in the concentration of Th2 cells observed in obesity results in a decrease in the concentration of anti-inflammatory cytokines, such as interleukin 4 (IL-4), interleukin 5 (IL-5), interleukin 10 (IL-10) and interleukin 13 (IL-13) [31]. The gene discussed is IL4; the disease is obesity due to melanocortin 4 receptor deficiency.