The Arabidopsis Information Resource (TAIR) maintains a database of genetic and molecular biology data for the model plant Arabidopsis thaliana. Note: Certain features on this site (commenting on genes or loci, registering a new mutant gene symbol) require setting up a free user name and password. Data available from TAIR include the complete genome sequence along with gene structure, gene product information, gene expression, DNA and seed stocks, genome maps, genetic and physical markers, publications, and information about the Arabidopsis research community. Gene product function data is updated every week from the latest published research literature and community data submissions. TAIR also provides extensive links to other Arabidopsis resources.