Supplementary Table S3 provides the correlation analysis of pre-and post-bronchodilation FEV1, FVC, FEV1/FVC among different sub-groups of the study subjects. The difference of SCGB1A1 concentration among the SMWD (% of expected) subgroups of all COPD subjects was also significantly different (p < 0.0001; Supplementary Table S1). The gene discussed is SCGB1A1; the disease is chronic obstructive pulmonary disease.