The expression levels of KLF9 were upregulated in lung tissues after smoke exposure (p < .05, Figure 1A,B), and inhibition of KLF9 significantly alleviated airway inflammation of COPD mice (p < .05, Figure 1C–E) and reduced NLRP3 expression levels in lung tissues (p < .05, Figure 1B). Here, NLRP3 is linked to chronic obstructive pulmonary disease.