Studies found that macrophages can cause inflammation in obese mice, causing macrophages to secrete interleukin-1 (IL-1), induction of type 3 innate lymphocyte activation, and secretion of interleukin-17A (Interleukin-17A, IL-17A) to induce AHR and airway inflammation, which is the key mechanism of obesity-related asthma. This evidence concerns the gene IL17A and obesity due to melanocortin 4 receptor deficiency.