Objective: Lung cancer still remains the leading cause of cancer deaths in the world and it lacks validated biomarkers to predict clinical outcome. The Hedgehog (Hh) pathway is critical for cell growth and differentiation. The aim of our study was to evaluate the role of the Hh signaling in the prediction of clinical outcome for advanced NSCLC.Methods: We determined the expression of Hh-related molecules including Ptch1 and Gli1 (nuclear and cytoplasmic) by immunohistochemistry in histologic samples (biopsies and surgical specimens) of advanced NSCLC patients. All the neoplastic area included in the slides was considered and both cytoplasmic and nuclear stainings were evaluated, according to the positive neoplastic cells. The intensity of the staining was evaluated and scored as follows: 0 (absent), 1+ (low), 2+ (medium) and 3+ (high).Results: We analyzed 35 lung cancer histological samples, 18 adenocarcinomas and 17 squamous cell carcinomas. Positivity of Gli1-cytoplasmic and Gli1-nuclear expression was expressed in adenocarcinoma at a significantly higher level and more frequently than compared to squamous cell carcinoma (p
