This project, originally begun when Dr. Bailey-Wilson was a Professor at Louisiana State University Medical Center, seeks to detect and understand genetic risk factors for lung cancer and possible gene-environment interactions. The purpose of this study is to identify a gene or genes that contribute to lung cancer susceptibility. The specific aims are to 1) collect family history and environmental risk factor data about lung cancer from lung cancer patients and their families and to also collect blood and tissue samples from a subset of the families that appear informative for linkage analysis; 2) genotype the biological samples for a genome wide set of marker loci; 3) perform a genome-wide linkage analysis to attempt to localize a lung cancer susceptibility locus (loci). In this fiscal year, family history and biologic samples have been collected from both new and previously studied families. Data collection is ongoing and expected to continue for several more years. Dr. Bailey-Wilson has been instrumental in founding the Genetic Epidemiology of Lung Cancer Consortium (GELCC) for the purpose of obtaining additional family data from a large group of collaborative investigators. Previous analysis of candidate regions in five GELCC families, including two of Dr. Bailey-Wilson's families gave some evidence of linkage in one of these regions. Two additional sets of families were genotyped for approximately 400 markers at the Center for Inherited Disease Research (CIDR) Genotype data from the genome wide screen of the larger number of families has been analyzed this year and the first genome-wide significant linkage of a lung cancer susceptibility locus has been published in this fiscal year. Several candidate regions have been suggested by these analyses and additional genotyping is ongoing in Dr. Anderson's lab to follow-up on these results. Several candidate loci have been sequenced in this region and sequencing is planned for approximately 90 more loci. A second set of families has been genotyped for the same GWS markers and analyses are ongoing. As head of the GELCC Analysis committee, Dr. Bailey-Wilson is in charge of the analyses of these data.