Created by the National Center for Biotechnology Information, UniGene is "an experimental system for automatically partitioning GenBank sequences into a non-redundant set of gene-oriented clusters." In addition to gene sequences, this Web site also offers thousands of novel expressed sequence tag (EST) sequences, a useful gene discovery resource. Organisms currently cataloged include human, rat, mouse, cow, zebrafish, clawed frog, fruitfly, mosquito, wheat, rice, barley, maize, and cress. Users may also access the Digital Differential Display to compare gene expression fingerprints for cancer cells and their normal counterparts. Other Web site features include query tips, FAQs, and relevant external links.