The development of immunoassays for the diagnosis of renal cancer promises significant improvements in clinical treatment. Monoclonal antibodies have defined numerous kidney-associated antigens. In at least one instance (ADAbp), an immunoassay has already been established that is helpful in the diagnosis of benign renal diseases. A similar approach may also be useful in renal cancer. Similarly, in at least one instance a previously undefined peptide (HHM factor) has been cloned and sequenced. Synthesis of this peptide and the production of antibodies to it is imminent. The possibility of measuring this peptide and/or the many other aberrantly produced peptides associated with this cancer would presumably mean a substantial improvement in early diagnosis and therefore cure rates in renal cancer. The final role of chromosome changes in the diagnosis and determination of prognosis cannot yet be defined.