TLR4 and chronic obstructive pulmonary disease: To further elucidate the roles of the TLR4 signaling pathway in the cellular response to LPS in COPD lung tissue, we analyzed the effects of Feikang Granule on the expression of TLR4, TLR2, p-Iκ B, IκB and NF-κ B p65 in COPD model rats.