Although proteomic technology has proved to be extremely powerful in basic research, its impact has not been as great in the clinical laboratory. The future, however, looks extremely positive because technologies, such as mass spectrometry and tissue microarrays, have continued to improve over the past several years. One of the most exciting developments, particularly in the area of mass spectrometry, is the ability to examine formalin-fixed paraffin-embedded tissue using these technologies. The almost inexhaustible supply of these tissues will enable proteomic laboratories access to clinically important specimens that will undoubtedly lead to a number of important discoveries in the near future.