Petta V, et al. - Herein, researchers assessed serum osteopontin (OPN) levels in patients with lung cancer (LC) and/or chronic obstructive pulmonary disease (COPD). Additionally, they looked at OPN prognostic performance in 1-year mortality in LC and also its diagnostic performance in LC among COPD patients. Among COPD patients, the presence of LC could be predicted by OPN levels ≥35 ng/mL. LC was identified as the major determinant for serum OPN in patients with LC and/or COPD. Overall, serum OPN might be a promising prognostic biomarker of LC and a diagnostic biomarker of LC among COPD patients.