The present invention provides novel polynucleotides encoding TRP-PLIK2 polypeptides, fragments and homologues thereof. The present invention also provides polynucleotides encoding variants and splice variants of TRP-PLIK2 polypeptides, TRP-PLIK2b, TRP-PLIK2c, and TRP-PLIK2d, respectively. 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 TRP-PLIK2, TRP-PLIK2b, TRP-PLIK2c, and TRP-PLIK2d polypeptides to the diagnosis, treatment, and/or prevention of various diseases and/or disorders related to these polypeptides. The invention further relates to screening methods for identifying agonists and antagonists of the polynucleotides and polypeptides of the present invention.