The NLRP3 inflammasome is a component of the human immune system, factors such as smoke exposure and infection can trigger systemic inflammatory responses via the NLRP3 signaling pathway, and overactivated NLRP3 signaling can upregulate IL-18 content and thus accelerate COPD development, so IL-18 levels can reflect the severity of patients' conditions. This evidence concerns the gene IL18 and chronic obstructive pulmonary disease.