This invention relates generally to a multimeric polypeptide complex/antigen which may be utilized in detecting or diagnosing diseases of the uterus such as uterine cancer. Furthermore, the invention relates to methods and kits, for example, which utilize this antigen or an antibody thereto. The complex itself comprises at least one EU250 polypeptide and at least one polypeptide which may be a BU101 polypeptide and/or a TU104 polypeptide. The complex may further comprise other, as yet unknown, polypeptide sequences.