We have tested 80 expressed sequence-tagged site (eSTS) markers assigned to human chromosome 11 by the Genexpress program on a panel of somatic cell hybrids containing parts of this chromosome, characterized by cytogenetic data, reference markers, and with respect to the Généthon microsatellite genetic map. Sixty-eight new gene transcripts have been assigned to 25 subregions, one of which was newly defined by five of the eSTS markers. The markers are distributed on the short and long arms in agreement with their physical length. The genic map thus obtained has been integrated with the cytogenetic, genetic, and disease maps. Two eSTS markers have been further mapped with respect to a yeast artificial chromosome (YAC) contig close to the brain-derived neurotrophic factor (BDNF) gene and thus provide potential candidate genes for the mental retardation phenotype of WAGR (Wilms' tumor, aniridia, genitourinary abnormalities and mental retardation) syndrome. Altogether, the 68 new gene transcripts localized here represent more than a threefold increase in the number of unknown regionalized genes that could reveal potential candidate genes for the numerous orphan pathologies associated with chromosome 11.