The main findings of this study were: 1) the selection and quantification of a unique NE-generated elastin fragment; 2) development of the EL-NE antibody which was specific towards a NE cleavage site on elastin and not towards other proteases; 3) development of a competitive ELISA assay for the assessment of NE-degraded elastin in serum; 4) demonstration that levels of NE-degraded elastin were significantly elevated in serum from IPF and lung cancer patients compared with healthy controls. The gene discussed is ELN; the disease is idiopathic pulmonary fibrosis.