In contrast, serum expression of MMP-1, -2, -13, TIMP-2, hyaluronic acid (HA), and procollagen III peptide (PIIIP) was unchanged between CF patients with a FEV1 (S1 Table) or VC (S2 Table) below and above 80%, or a ratio of FEV1/VC (S3Table) above and below 70%. Here, TIMP2 is linked to cystic fibrosis.