A human cholecystokinin-B/gastrin receptor cDNA (CCKBR) has been recently cloned and its transcriptional product has been characterized. The cDNA probe was mapped by fluorescence in situ hybridization to chromosome 11 at bands p15.5-->p15.4. The localization of this receptor gene provides a useful marker for this region of chromosome 11 permitting the identification of diseases involving the gene and interactions with other genes.