Updated project metadata. Idiopathic pulmonary fibrosis (IPF) is a form of chronic and irreversible fibrosing interstitial pneumonia of unknown aetiology, with an average survival time of 3-5 years after diagnosis. Emerging evidence suggests that IPF increases the risk of lung carcinogenesis. Both diseases show similarities in terms of risk factors, such as history of smoking, concomitant emphysema, and viral infections, besides sharing similar pathogenic pathways. Lung cancer diagnosis is often difficult in IPF patients because of the diffuse lung injuries and abnormalities due to the underlying fibrosis. This is reflected in the lack of optimal therapeutic strategies for patients with both diseases. For this purpose, we performed a proteomic study on bronchoalveolar lavage (BAL) samples from IPF, LC associated with IPF (LC-IPF) patients, and healthy controls (CTRL). Molecular pathways involved in inflammation, immune response, lipid metabolism and cell adhesion were found for the dysregulated proteins in LC-IPF, of which TTHY, APOA1, S10A9, RET4, GDRI1 and PROF1. The correlation test revealed a relationship between inflammation-related proteins and proteins associated with lipid metabolism. Also, the up-regulation of PROF1 in LC-IPF BAL and S10A9 in LC-IPF serum was validated. While APOA1 and APOE were validated as highly abundant in IPF BAL and low abundant in IPF serum. We evaluated nicotinamide phosphoribosyltransferase levels in serum highlighting its down-regulation in LC-IPF. Our retrospective analyses on BAL of IPF and LC-IPF patients extrapolate some potential biomarkers whose further evaluation at the serum level, permits the measurement of these potential biomarkers with a less invasive procedure.