A set of contiguous and partially overlapping RNA sequences and polypeptides encoded thereby, designated as PS190 and transcribed from prostate tissue is described. These sequences are useful for the detecting, diagnosing, staging, monitoring, prognosticating, preventing or treating, or determining the predisposition of an individual to diseases and conditions of the prostate, such as prostate cancer. Also provided are antibodies which specifically bind to PS190-encoded polypeptide or protein, and agonists or inhibitors which prevent action of the tissue-specific PS190 polypeptide, which molecules are useful for the therapeutic treatment of prostate diseases, tumors or metastases.