In accordance with the results on pulmonary function, the multivariate adjusted odds ratio for COPD was not increased in E292V heterozygotes compared with wildtypes (odds ratio 1.10 (0.83-1.46)), while surfactant protein-B 121ins2 heterozygotes and α1-antitrypsin ZZ homozygotes had increased odds ratios for COPD of 2.8 (1.0-8.1) and 6.6 (1.7-26) (Additional file 9). Here, SFTPB is linked to chronic obstructive pulmonary disease.