The present invention relates to PSGR, a novel prostate specific gene with homology to a G-protein coupled receptor overexpressed in prostate cancer. More specifically, the invention relates to PSGR polynucleotides and the polypeptides encoded by these polynucleotides, and the use of PSGR polynucleotides and polypeptides for detecting disorders of the reproductive system, including disorders of the prostate, particularly the presence of cancer. This invention relates to PSGR polynucleotides and polypeptides as well as vectors, host cells, antibodies directed to PSGR polynucleotides and polypeptides and recombinant and synthetic methods for producing the same. Also provided are methods for diagnosing, treating, preventing, and/or prognosing disorders related to the prostate, including cancer. The invention further relates to screening methods for identifying agonists and antagonists of PSGR polynucleotides and polypeptides of the invention and methods and/or compositions for inhibiting or enhancing the production and/or function of the PSGR polypeptides of the present invention.