TNF and obesity due to melanocortin 4 receptor deficiency: Likewise, adipocyte accumulation due to obesity secretes adipocytokines, such as Interleukin-6, TNF-α, interferon-γ, and leptin, stimulates bronchial smooth muscle contraction, and induces macrophages to move into the alveoli, provoking chronic inflammation damage to the alveoli and airway and increasing respiratory symptoms [39].