To assess the presence of proteins that could be indicative of the lung function decline and therefore of the disease severity, we thought to focus on the up-regulated proteins in patients with IPF Stage II or with compromised lung function (e.g FVC<75, DLCO<55), not further investigated, in the present study, the differentially and uniquely expressed proteins in Stage I patients (e.g SH3BGRL3, Figure 3A) as well as patients having FVC>75 and DLCO >55 (data not shown). The gene discussed is SH3BGRL3; the disease is idiopathic pulmonary fibrosis.