Non-small cell lung cancer (NSCLC) is a subtype of lung cancer and accounts for approximately 80% of lung cancer cases. For several years, chemotherapy treatment was the only optional treatment. The combination of two drugs - based on the platinum group, was the first line therapy. However the prognosis for patients with metastatic stage lung cancer is poor with a median survival time of 9-12 months. Recent studies of molecular biology in lung cancer have expanded our understanding of the processes involved in cancer. Subsequently developed targeted drugs operate on cancer cell mechanisms, such as antibodies and kinase inhibitors. However, the majority of patients with metastatic lung cancer still do not benefit from clinical therapy. One reason for this is the development of drug resistance. Today, the major focus is on the development of a personal pharmacological approach - targeted therapy. Progress has been made in the understanding of molecular biomarkers in the cell, due to the execution of many studies that incorporate the new treatments for these patients.