The study of oncogenes, tumor suppressor genes and other growth regulatory cellular components have advanced rapidly during the last few years. Markers of these genes and their protein products are already clinically useful for a number of human neoplasmes,diagnosis of prostate cancer is usually readily made on morphological grounds by use of traditional histological parameters, including architecture, nuclear features, and the presence or absence of a basal cell layer. However, in morphologically equivocal cases the histopathologist may have to resort to the use of immunohistochemistry to resolve the differential diagnosis.