Interestingly, in a model of chronic obstructive pulmonary disease (COPD) induced by LPS combined with cigarette smoke for 4 weeks, 24.3 mg/kg sodium houttuyfonate decreased the mRNA levels of TLR4, MyD88, and NF-κB p65 (Wu et al., 2017), however, considering the differences in the adaptability of humans and rats to cigarette smoke, this research still needs more investigation. This evidence concerns the gene TLR4 and chronic obstructive pulmonary disease.