The present invention provides novel polynucleotides encoding CAN-12 polypeptides, fragments and homologues thereof. The present invention also provides polynucleotides encoding variants of CAN-12 polypeptides, CAN-12v1 and CAN-12v2. Also provided are vectors, host cells, antibodies, and recombinant and synthetic methods for producing said polypeptides. The invention further relates to diagnostic and therapeutic methods for applying these novel CAN-12, CAN-12v1, and CAN-12v2 polypeptides to the diagnosis, treatment, and/or prevention of various diseases and/or disorders related to these polypeptides, particularly neuro- and musculo-degenerative conditions. The invention further relates to screening methods for identifying agonists and antagonists of the polynucleotides and polypeptides of the present invention.