Interestingly, the TLR3 agonist poly I:C was able to increase significantly the expression of TLR3 (Figure 5B, C, and D) and TRIF (Figure 6B, C, and D) in HBECs from smokers with COPD and to a lesser extent in smokers and non-smoker subjects. This evidence concerns the gene TLR3 and chronic obstructive pulmonary disease.