A very unique biomedical research institution, "The Jackson Laboratory, a non-profit institution, is the world's largest mammalian genetic research facility." As such, Jackson provides universities and hospitals worldwide with millions of mice -- representing more than 2,500 varieties -- each year. This website offering from Jackson Laboratory, located in Bar Harbor, Maine, allows visitors to solicit valuable information on the mouse genome. "The Gene Expression Database (GXD) is a community resource for gene expression information from the laboratory mouse. GXD stores and integrates different types of expression data and makes these data freely available in formats appropriate for comprehensive analysis." At the site, visitors can learn about how to acquire data and search for via the Gene Expression Query Forms. Also of interest are the sections devoted to Who's Who in GXD and links to Selected Publications.