IL6 and chronic obstructive pulmonary disease: The proinflammatory cytokines and chemokines (TNF-α, IL-1, IL-6, and IL-8), the signaling pathways (NF-κB and MAPK pathways), and various stress-related molecules (SOD, MDA, GSH) participate in the different pathological stages of COPD (Yang et al., 2020).