Neutrophils play a central role in the pathophysiology of emphysema associated with AATD97, and pulmonary disease is thought to develop, in part, from an imbalance of proteinases and AAT, although AAT has many non-proteolytic functions which protect against infection and inflammation, including immunomodulation and anti-microbial activity. Here, SERPINA1 is linked to pulmonary emphysema.