The majority of non-small-cell lung cancer (NSCLC) patients present with locally advanced (35%) or metastatic disease (40%); in this setting, it is of the utmost importance to balance efficacy with toxicity. However, with platinum combinations, survival has reached a " plateau" , with median overall survival times of a mere 10-12 months, making it mandatory to search for new strategies and to identify more effective treatment. Molecular characteristics can be more informative than clinical features in predicting clinical benefit, and the identification of molecular markers can help define subgroups of patients who are likely to respond to different treatments, thus avoiding unnecessary toxicities and costs and providing the maximum benefit to each patient. Here we review research on biomarker assessment that was presented during the Molecular Biology Workshop held in Palma de Mallorca on 25 November 2010, during the Fifth Educational Symposium of the Spanish Lung Cancer Group. © 2011. ; Bover, I.; Rolfo, C.; Jantus Lewintre, E.; Sirera Pérez, R.; Camps, C.; Chaib, I.; Ramirez-Serrano, JL. (2011). Fifth Educational Symposium of the Spanish Lung Cancer Group: report on the Molecular Biology Workshop. Lung Cancer. 74(3):535-543. doi:10.1016/j.lungcan.2011.04.016. ; Senia ; 535 ; 543 ; 74 ; 3