It was observed that IL‐18 and IL‐18 receptor (IL‐18R) were strongly expressed in the lungs of fatal asthma 4, serum IL‐18 levels were significantly high in asthmatic children 5 and IL‐18 variants were significantly associated with asthma severity 6, implicating that IL‐18 likely contributes to the development of asthma. This evidence concerns the gene IL18R1 and asthma.