Disclosed are novel GPCR (G Protein Coupled Receptor) proteins and genes encoding the same. Also provided is the use of the proteins and the genes. Particularly, contemplated are a novel GPCR (G Protein Coupled Receptor) polypeptide, a polynucleotide coding for the same, a recombinant vector carrying the polynucleotide or a fragment thereof, host cells transformed with the vector, a transgenic animal infected with the vector. Also, a composition for detecting a cancer marker, comprising an agent capable of measuring the expression level of mRNA or protein of the GPCR polynucleotide, a kit for the diagnosis of cancer, comprising the composition, and a method for detecting the GPCR polypeptide and a gene encoding the polypeptide are provided. Further, a composition for the treatment and prevention of cancer, comprising an oligonucleotide inhibiting the expression of a gene encoding the GPCR polypeptide or an antibody against the GPCR protein, and a method for screening a modulator of the GPCR protein or a cancer therapeutic agent are provided.