The association of various inheritance models for TLR9 rs5743836 (T1237C) showed that the dominant subjects with the TLR-9 mutant (T/C) genotype related to COPD exacerbation risk was the best inheritance model (OR 2.4, 0.99 to 5.82, p = 0.05). This evidence concerns the gene TLR9 and chronic obstructive pulmonary disease.