UniGene

From DrugPedia: A Wikipedia for Drug discovery

UniGene is an experimental system for automatically partitioning GenBank sequences into a non-redundant set of gene-oriented clusters. Each UniGene cluster contains sequences that represent a unique gene, as well as related information such as the tissue types in which the gene has been expressed and map location.

More detail at http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=unigene