SPRED1 and airway hyperresponsiveness: This may result from: (1) miR‐126 directly affects airway pathology through regulating of several genes (such as SPRED‐1) and signaling pathways (such as TLR4 signaling pathway), thus aggravating the disease severity of COPD patients12, 26; (2) miR‐126 promotes the release of inflammatory factors, which leads to acute and chronic airway inflammation, and subsequently causes pathophysiological changes such as reversible airway restriction, airway remodeling, and airway hyperresponsiveness, then exacerbates disease severity in COPD patients.27, 28