In contrast, FN mRNA expression gradually increased following stimulation with TGF-β1 over the time course with significant increases at 48 h and 72 h time points in COPD (p<0.01, n = 7) ASM cells, and significant increases at 24 h, 48 h, and 72 h time points in non-COPD (p<0.01, n = 5) ASM cells (Fig. S3). Here, FN1 is linked to chronic obstructive pulmonary disease.