TLR4 and chronic obstructive pulmonary disease: Of note, 5 immune-related pathways (map04659: Th17 cell differentiation; map04657: IL-17 signaling pathway; map04625: C-type lectin receptor signaling pathway; map04622: RIG-I-like receptor signaling pathway; map04624: Toll and Imd signaling pathway) were significantly enriched in the COPD group.