In our opinion, there are four mechanisms of the effect of insulin resistance in asthma: (i) aging is associated with insulin resistance, which can lead to premature airway closure and airway damage, (ii) insulin directly contributes to airway dysfunction by causing airway inflammation through the activation of immunological and structural cells in the lungs, (iii) insulin can directly induce airway hyperresponsiveness by promoting the deposition of collagen fibroblasts in the airways, (iv) insulin is a pleiotropic hormone that affects endothelial cells in a variety of ways. The gene discussed is INS; the disease is asthma.