TLR4 and chronic obstructive pulmonary disease: For this purpose we investigated the prevalence and any possible associations of common TLR polymorphisms (TLR2-R753Q, TLR4-D299G, and TLR4-T399I) in a group of 240 heavy smokers (>20 pack years), without overt atherosclerosis disease, of whom 136 had developed COPD and 104 had not.