Non-small cell lung SP600125 distributor cancer is the leading cause of cancer mortality worldwide . Over 45% of NSCLC patients present with 194413-58-6 unresectable late-stage disease in the United States . A combined modality therapy is the current standard of care for patients with stage III NSCLC with good performance status . Numerous clinical trials have shown that concurrent chemoradiation offers a significant survival advantage over sequential chemoradiation . Although concurrent chemoradiotherapy significantly improves the survival of patients with locally advanced disease, the majority of patients still die within 5 years because of locoregional or distant disease progression . The stage IV patients are usually offered palliative chemotherapy and supportive care . There is a wide variability in patients�� response to chemoradiation and clinicopathological variables alone do not provide satisfactory guidance for the decision of treatment strategy. The application of pharmacogenomics may improve the prediction of response and help clinicians determine cancer treatments for individual NSCLC patient according to his unique genetic background. Therefore, in this study, we aimed to identify genetic predictors for clinical outcomes of late stage NSCLC patients. G proteins are important cellular signal transduction molecules that are expressed in all human cells . They are activated by G protein-coupled receptors and thereby may transduce extracellular signals into the interior of a cell . GPCRs are a family of seventransmembrane domain receptors. When GPCRs traduce a signal inside the cell, the extracellular domain of GPCR first binds to the signal molecules, and then the intracellular domain of GPCR activates a heterotrimeric G-protein. The heterotrimeric G protein functions as ����molecular switches���� and can activate a cascade of signaling factors and downstream target activation . This G protein-coupled biological process requires fine-tuning through accessory molecules such as the regulator of G-protein signaling . RGS proteins are a big family of over 30 intracellular proteins , which can negatively modulate GPCRs signaling pathways . RGS are multi-functional, GTPase-accelerating proteins that promote GTP hydrolysis by the alpha subunit of heterotrimeric G proteins, thereby inactivating the G protein and rapidly switching off GPCR signaling pathways . All RGS proteins contain a RGS domain ,which is required for their activities , and these RGS domains mediate the interaction with other signaling proteins, allowing RGS proteins to serve as signaling scaffolds .