Abstract: The present disclosure relates generally to the membrane transporter NaPi2b (SLC34A2) as a target for therapy, including immunotherapy, and particularly cancer therapy. The SLC34A2 epitope peptide encompassing amino acids 312-340 of SLC34A2 has been identified as an ovarian cancer epitope using the monoclonal antibody MX35. The invention also relates to the use of SLC34A2 and particularly SLC34A2 peptides in generating antibodies which have anti-tumor or anti-cancer activity or in stimulating an immunological response. The invention further relates to antibodies specifically directed against NaPi2b (SLC34A2) and the SLC34A2 peptide (s), including veneered, chimeric, single chain and humanized antibodies. Methods for generating an immune response and for treatment of tumors and cancer are also provided. Assays for screening and identifying compounds directed against SLC34A2, including the SLC34A2 epitope peptide, and additional antibodies are provided.

Abstract: Polynucleotide molecules and polypeptide molecules A34 and A33-like 3 are described, as well as antibodies to polypeptide molecules A34 and A33-like 3. Also described are methods of detecting cancers expressing these polypeptides, and methods and kits for diagnosing said cancers, and methods of inhibiting effects of a cancer in a patient.