The remarkable success of epidermal growth factor receptor (EGFR) and anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors in patients with EGFR mutations and ALK rearrangements, respectively, introduced the era of targeted therapy in advanced non-small cell lung cancer (NSCLC), shifting treatment from platinum-based combination chemotherapy to molecularly tailored therapy. Recent genomic studies in lung adenocarcinoma identified other potential therapeutic targets, including ROS1 rearrangements, RET fusions, MET amplification, and activating mutations in BRAF, HER2, and KRAS in frequencies exceeding 1%. Lung cancers that harbor these genomic changes can potentially be targeted with agents approved for other indications or under clinical development. The need to generate increasing amounts of genomic information should prompt health-care providers to be mindful of the amounts of tissue needed for these assays when planning diagnostic procedures. In this review, we summarize oncogenic drivers in NSCLC that can be currently detected, highlight their potential therapeutic implications, and discuss practical considerations for successful application of tumor genotyping in clinical decision making.Keywords: lung cancer; cancer genomics; molecular targeted therapy Lung cancer remains the leading cause of cancer-related mortality in the United States and worldwide. Approximately 85% of patients are diagnosed with non-small cell lung cancer (NSCLC), and most present with advanced disease that is not amenable to curative therapy. For these patients, cytotoxic chemotherapy offers modest prolongation in survival. Over the past 2 decades, modifications of chemotherapy combinations, the addition of monoclonal antibodies, including bevacizumab and cetuximab, and the incorporation of histologic subtype into treatment decisions have added incrementally to the survival of patients with advanced NSCLC. However, therapeutic outcomes appear to have reached a plateau, with response rates of 20 to 35% and median survival of 8 to 12 months (1-3). Recently, clinical and laboratory research have led to a better understanding of the molecular pathogenesis that causes lung cancer. The ongoing research of patients with NSCLC and their tumors has demonstrated that NSCLC can be further defined at the molecular level by the identification and characterization of oncogenic drivers that occur in genes critical to cellular proliferation and survival, leading to aberrant activation of signaling proteins that induce sustained growth of the lung cancer cells. These advances in the molecular pathogenesis of NSCLC have prompted investigators to systematically characterize lung cancers for these oncogenic drivers and treat with appropriate targeted therapies. A cohort of patients can now be prospectively identified who have significantly improved outcomes with such therapies, with median survival in excess of 2 years, necessitating the routine identification of these genomically defined patient subsets. In this perspective, we review oncogenic ...