Abstract Lung cancer is the leading cause of cancer related deaths worldwide in both men and women. Metastasis is responsible for most lung cancer related deaths; therefore, a better understanding of the metastatic processes and therapies designed to prevent the spread of cancer cells are greatly needed. The specific mechanisms that promote metastases have not been fully elucidated. Among all known chemokine receptors involved in cancer progression, most cancer cells including lung cancer express CXCR4. Furthermore, involvement of CXCR4 and CCR7 in breast cancer and CXCR4, CCR9 and CX3CR1 in prostate cancer progression further indicates that multiple chemokine receptors are involved in dictating the multi-step process of metastasis. In this study, we show significantly higher expression of CXCR6 and CXCL16 in lung cancer tissues compared to normal matched tissues. Expression of CXCR6 was significantly higher in adeno- carcinoma compared to squamous cell carcinoma. It addition to these, serum levels of CXCL16, the only natural ligand for CXCR6, was also significantly higher in lung cancer patients compared to normal healthy donor. Furthermore, serum CXCL16 was also significantly higher in patients with adenocarcinoma compared to patients with squamous cell carcinoma. Impact of this chemokines-receptor axis was determined in lung cancer cell lines in vitro, which express CXCR6 and CXCL16. Like tissues, lung cancer cells showed higher expression of CXCR6 and CXCL16 compared to normal lung epithelial cells (NuLi-1). Interestingly, expression of CXCR6 was highest in cell lines derived form adenocarcinoma followed by cell lines from squamous cell carcinoma. Furthermore, we demonstrate that CXCR6 and soluble CXCL16 interaction plays a crucial role in lung cancer cells migration and invasion. The mechanism underlying these clinically and biologically important findings need to be further explored. Increased serum CXCL16 in lung cancer patients with metastatic disease required further validation as a potential therapeutic target and/or diagnostic marker for lung cancer. Citation Format: Hina Mir, Pranav Gupta, Rajesh Singh, Praveen K. Sharma, Gurpreet Kaur, Ashley B. Ward, William E. Grizzle, James W. Lillard, Shailesh Singh. Clinical and biological significance of CXCR6 in lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4003. doi:10.1158/1538-7445.AM2014-4003