Fig. 1

a Venn diagram of the three data sets: The Venn diagram shows the numbers of the genes which are mapped to nominally differentially methylated CpG sites or significantly differentially expressed in the data set and their overlap. For b–e The sizes of the genes relate to their degree within this module. Genes that are associated with COPD are represented as a square. Genes that have a heavier border connect to other modules. The blue edges represent physical interactions, the red edges functional interactions, and green edges represent both. b Fetal lung methylation module: The module consists of 50 significant genes from the fetal lung methylation data set. c COPD expression disease module: The module consists of 64 significant genes from the COPD gene expression data set. d COPD methylation disease module: The module consists of 37 significant genes from the COPD methylation data set. e The three modules form a connected component in the HumanNet-FN: The fetal lung methylation module (pink), the COPD expression disease module (turquoise), and the COPD methylation disease module (yellow) form one large connected component. The sizes of the nodes correspond to their degree within the shown component