This invention provides novel carbonic anhydrase (CAIX) nucleic acid and peptide sequences, as well as related methods and compositions, including anti-cancer immunogenic agent(s) (e.g. vaccines and chimeric molecules) that elicit an immune response specifically directed against cancer cells expressing a CAIX antigenic marker. The novel CAIX variant and related compositions are useful in a wide variety of treatment modalities including, but not limited to protein vaccination, DNA vaccination, and adoptive immunotherapy.