Abstract: The present invention provides novel isolated ARP/BRP polynucleotides and the membrane-associated or secreted polypeptides encoded by the ARP/BRP polynucleotides. Also provided are ARP and BRP protein multimers. Further provided are the antibodies that immunospecifically bind to a ARP/BRP polypeptide or any derivative, variant, mutant or fragment of the ARP/BRP polypeptide, a ARP/BRP multimer polynucleotide or antibody. The invention additionally provides methods in which the ARP/ BRP polypeptide, multimer, polynucleotide and antibody are utilized in the detection and treatment of a broad range of pathological states, e.g. reproductive disorder, as well as to other uses.