The breast basic conserved gene (D16S444E) is a candidate tumor suppressor gene previously mapped to human chromosome 16. We determined the map position of D16S444E more precisely using a somatic mouse x human hybrid panel and fluorescence in situ hybridization on metaphase spreads and interphase nuclei. We show that the D16S444E gene is localized on band 16q24.3 and is located between APRT and D16S44.