In patients with COPD, the activation of the pro-inflammatory transcription factor NFκB in macrophages by CS or other irritants leads to the increased expression of chemokines such as IL8, CXCL1, CXCL6, and CXCL8, promoting the influx of neutrophils into the lungs and resulting in neutrophilic inflammation [117,118]. Here, CXCL1 is linked to chronic obstructive pulmonary disease.