For instance, evaluating the activity of HAS2, the expression levels and fractions of HMW-HA and LMW-HA, and the concentrations of G-CSF and TGF-β in lung specimens from COPD patients, as well as examining their correlation with FEV1 decline, the frequency of acute exacerbations, and prognosis, is expected to enhance their clinical value. Here, TGFB1 is linked to chronic obstructive pulmonary disease.