title: A DNA microarray survey of gene expression in normal human tissues.
abstract: BACKGROUND
  Numerous studies have used DNA microarrays to survey gene expression in cancer and other disease states. Comparatively little is known about the genes expressed across the gamut of normal human tissues. Systematic studies of global gene-expression patterns, by linking variation in the expression of specific genes to phenotypic variation in the cells or tissues in which they are expressed, provide clues to the molecular organization of diverse cells and to the potential roles of the genes.
  
  
  RESULTS
  Here we describe a systematic survey of gene expression in 115 human tissue samples representing 35 different tissue types, using cDNA microarrays representing approximately 26,000 different human genes. Unsupervised hierarchical cluster analysis of the gene-expression patterns in these tissues identified clusters of genes with related biological functions and grouped the tissue specimens in a pattern that reflected their anatomic locations, cellular compositions or physiologic functions. In unsupervised and supervised analyses, tissue-specific patterns of gene expression were readily discernable. By comparative hybridization to normal genomic DNA, we were also able to estimate transcript abundances for expressed genes.
  
  
  CONCLUSIONS
  Our dataset provides a baseline for comparison to diseased tissues, and will aid in the identification of tissue-specific functions. In addition, our analysis identifies potential molecular markers for detection of injury to specific organs and tissues, and provides a foundation for selection of potential targets for selective anticancer therapy.
authors.affiliation: Department of Pathology, Stanford University School of Medicine, 269 Campus Drive, CCSR 3245A, Stanford, CA 94305-5176, USA. shyamsundar@corgentech.com
authors.forename: Radha
authors.initials: R
authors.lastname: Shyamsundar
authors.forename: Young H
authors.initials: YH
authors.lastname: Kim
authors.forename: John P
authors.initials: JP
authors.lastname: Higgins
authors.forename: Kelli
authors.initials: K
authors.lastname: Montgomery
authors.forename: Michelle
authors.initials: M
authors.lastname: Jorden
authors.forename: Anand
authors.initials: A
authors.lastname: Sethuraman
authors.forename: Matt
authors.initials: M
authors.lastname: van de Rijn
authors.forename: David
authors.initials: D
authors.lastname: Botstein
authors.forename: Patrick O
authors.initials: PO
authors.lastname: Brown
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Pollack
mesh_terms: D016000:Cluster Analysis; D020869:Gene Expression Profiling; D023281:Genomics / Q000379:methods; D006801:Humans; D020411:Oligonucleotide Array Sequence Analysis; D012333:RNA, Messenger / Q000378:metabolism; D014018:Tissue Distribution
chemical_list: D012333:RNA, Messenger