A set of contiguous and partially overlapping cDNA sequences and polypeptides encoded thereby, designated as BL172 and transcribed from urinary tract tissue, is described. These sequences are useful for the detecting, diagnosing, staging, monitoring, prognosticating, in vivo imaging, preventing or treating, or determining the predisposition of an individual to diseases and conditions of the urinary tract, such as urinary tract cancer. Also provided are antibodies which specifically bind to BL172-encoded polypeptide or protein, and agonists or inhibitors which prevent action of the tissue-specific BL172 polypeptide, which molecules are useful for the therapeutic treatment of urinary tract diseases, tumors or metastases.