The invention provides a polypeptide. The invention also provides a nucleic acid sequence encoding the polypeptide, a nucleic acid construct comprising the nucleic acid, an expression vector, a host cell, and an antigen-presenting cell presenting the polypeptide on the cell surface and an immune effector cell thereof. The present invention also provides a pharmaceutical composition, a vaccine, anantibody, a therapeutic method, a diagnostic method, and a diagnostic device comprising the polypeptide. The invention also provides uses of the polypeptide in preparation of a vaccine, a diagnostic tumor kit or a pharmaceutical composition, and uses of the polypeptide and the nucleic acid as an inspection target in diagnosis of a tumor.