Selected enriched canonical pathways are given in Table 1 and include interferon signaling, liver X receptor (LXR)/retinoid X receptor (RXR) activation, glucocorticoid receptor signaling, p38 mitogen-activated protein kinase (MAPK) signaling, IL13 signaling pathway, Toll like receptor signaling, peroxisome proliferator-activated receptors (PPAR) signaling, aryl hydrocarbon receptor (AHR) signaling, IL17 signaling, and airway pathology in chronic obstructive pulmonary disease (COPD). Here, PPARA is linked to chronic obstructive pulmonary disease.