Nucleic Acids Research, 2007, Vol. 35, Web Server issue W157 Figure 3. Screenshots of GeneHub-GEPIS web output pages. (A). Tissue Expression Proﬁle Chart and GeneHub-GEPIS result table. The bar chart displays the normal (blue) and tumor (yellow) DEU values of each type of tissue, and the table shows numeric data and statistics. The user can select tissues and specify a genomic range in this page to draw Regional GEPIS Atlas. (B) The gene summary section provides a short description of gene function, species, genomic coordinates and synonyms. It provides a link to navigate to the result for a gene’s ortholog, links to download results, view EST hits by libraries, and view additional graphic charts, and links to additional web resources such as the UCSC genome browser. Since the backend data can be potentially useful for other purposes, we provide a download page where all backend data can be retrieved. These include gene mapping and cross-reference data, exon and boundary deﬁnitions, EST mapping and associated library informa- tion, pre-computed expression results for all pre-deﬁned genes, and detailed EST library distribution information for each gene. Such ﬁles can be used by power users for global surveys of expression across a large number of genes. CONCLUDING REMARKS Despite the increasing prevalence of microarray data, ESTs remain as a signiﬁcant source of data for expression analysis, and can provide beneﬁts over microarrays in some cases (7). However, the value of EST data can only be fully realized with the availability of powerful and user- friendly tools that transform loosely organized EST information into meaningful expression results. Guided by input from the user community, we aimed to make