To address CF lung manifestation and pulmonary fibrosis as a potential confounder of the above results of a significant regulation of TIMP-4, Endoglin and PTX3 in the presence of liver disease, we assessed their serum expression in CF patients with a forced expiratory volume in one second (FEV1) below and above 70%, with a vital capacity (VC) of below and above 80%, and with a ratio between FEV1 and VC below and above 70% (FEV1/VC), which serve as established indicators of CF lung disease and have been the primary outcome in many clinical trials [17], [22], [23], [24]. This evidence concerns the gene TIMP4 and pulmonary fibrosis.