Incremental progress will likely continue to be made in the treatment of lung cancer using the conventional treatment modalities. However, there is now hope that the development of noncross-resistant modalities that can be accomplished using the technology of gene transfer may hasten the progress made in this disease. Although significant progress has been made, the practical application of the various strategies to the treatment of cancer patients in clinical trials has yielded only very limited results. For the strategies of introducing suicide genes, replacing defective tumor-suppressor genes, and inactivating oncogenes, considerable progress will need to be made particularly with regard to the ability of vectors to selectively and efficiently target tumor cells in order for many of these strategies to become effective. With regard to the application of gene therapy to immunotherapy, major responses are not likely at this time since these innovative therapies are being developed in patients with advanced disease. However, it is very likely that these pioneering clinical trials will provide important clinical and immunological information that will be the basis for future attempts to effectively harness the immune system against lung cancer.