In a large population study of patients enrolled in the Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA), Ferrarotti et al.9 found narrower serum AAT ranges compared with other studies and described a cutoff level at 110 mg/dL to distinguish homozygous Pi*MM from heterozygous Pi*MZ and Pi*SZ alleles. Here, SERPINA1 is linked to lung disorder.