SERPINA1 and pulmonary emphysema: The Z mutation (E342K) of α1-antitrypsin (α1-AT),4 carried by 4% of Northern Europeans, predisposes to the early onset of emphysema due to decreased functional α1-AT in the lung and to liver cirrhosis due to accumulation of α1-AT polymers in the endoplasmic reticulum of hepatocytes (9, –, 12).