One of the seven communities (community 202) which was validated by both differential expression and DNA methylation contains two previously identified COPD GWAS genes located in a genome-wide significant region: IREB2 (iron responsive element binding protein 2) and CHRNA5 (cholinergic receptor nicotinic alpha 5 subunit) [23–25]. Here, IREB2 is linked to chronic obstructive pulmonary disease.