Fig. 7. Indirect immunoperoxidase staining of prostate and breast with anti-Ki67 and anti-Mcm2 monoclonal antibodies. (A,B) In prostate, only a small number of glandular epithelial cells express Mcm2 (A) and Ki67 (B), which are restricted to the basal cell population (x158). (C) A high proportion of mammary luminal epithelial acinar cells in resting pre-menopausal breast show Mcm2 expression (x158). (D) In contrast to Mcm2, Ki67 is only expressed in a small number of mammary luminal epithelial acinar cells in pre-menopausal breast (x158). (E) In breast tissue from pregnant females the proportion of Mcm2 expressing acinar cells increases and now also includes the outer myoepithlial cell population including some specialised stromal cells (x158). (F) In breast tissue from lactating females the majority of mammary acinar cells lack Mcm2 expression (x158).