GP88 (progranulin) is a growth and survival factor implicated in tumorigenesis and drug resistance. Previous studies showed that GP88 was expressed in breast cancer tissue in inverse correlation with survival. This study evaluates GP88 tissue expression in localized/locally advanced lung cancer and GP88 serum levels in advanced disease. GP88 expression was determined by immunohistochemistry in tumor tissue from non-small cell carcinoma (NSCLC) patients, 85 with localized (Stage I-II) and 40 with locally advanced disease (Stage IIIa) and correlated with clinical outcome. Serum GP88 levels from Stage IIIb/IV patients, quantified by Enzyme Immunoassay (EIA) were compared to GP88 levels from patients with Chronic Obstructive Pulmonary Disease (COPD) and healthy individuals. GP88 was expressed in >80% adenocarcinoma and squamous cell carcinoma in contrast to normal lung or small cell lung cancer. There was a statistically significant inverse association of GP88 expression (GP88 Immunohistochemistry score 3+ vs.