GSTCD and chronic obstructive pulmonary disease: In particular, we confirmed association within the region of HTR4 in population- and family-based analysis, associations within the regions of CHRNA3/5; FAM13A; EEFSEC; RIN3; and HHIP in analysis of COPD-enriched samples, and associations in/near CHRNA3/5; GSTCD; AGER; DSP; RIN3; HHIP; FAM13A; THSD4; and EEFSEC in combined analysis incorporating both population-based and COPD-enriched strata (Supplementary Data 2).