COPD exacerbations are characterized by high neutrophil counts, and high levels of C-reactive protein (CRP), as well as inflammatory cytokines including tumor necrosis factor α (TNFα), interleukin-1 (IL1), interleukin-8 (IL8) and IL6 (Bradford et al., 2017; Xiong et al., 2017; Nuñez et al., 2020). Here, IL6 is linked to chronic obstructive pulmonary disease.