HHIP and pulmonary emphysema: As the top differentially expressed gene was HMGB1, a known interactor of the COPD and emphysema gene AGER, we sought to determine whether there was differential expression of the putative interactors for the first three identified COPD GWAS genes: IREB2, HHIP and FAM13A. Using a combination of experimental datasets and network analyses, we observed strong enrichment for putative interactors of IREB2, HHIP, and FAM13A. We identified a gene co-expression module strongly associated with COPD, and enriched for B cell functions.