Our work in an ovarian cancer cell line stained immunohistochemically and by immunofluorescence for MCM-2, MCM-5 and Ki-67 verified that MCM-positive cells (especially MCM-5) outnumbered Ki-67-positive cells in unsynchronised cells (98 vs 88%) and that this difference became even greater in synchronised cells arrested in G1 (79 vs 55%). The gene discussed is MCM5; the disease is ovarian cancer.