A previous study similarly demonstrated overexpression of Egr-1 associated with increased levels of TGF-β and connective tissue growth factor in lung fibroblasts from patients with chronic obstructive pulmonary diseases [36], and other studies have shown that TGFβ induces rapid but transient expression of Egr-1 that results in stimulation of collagen gene expression [37]. Here, EGR1 is linked to chronic obstructive pulmonary disease.