IL17A and chronic obstructive pulmonary disease: Candidate IL-17 signature genes were enriched among smokers with COPD compared with those without (mean of the zero-centered log2 gene expression in those with COPD = 0.11 ± 0.27 vs. without = –0.60 ± 0.19, P = 6.10 × 10–6; Supplemental Figure 1; supplemental material available online with this article; https://doi.org/10.1172/JCI121087DS1).