Inhibition of Plk4 by small molecules significantly reduced cell proliferation in several cell lines derived from a number of cancers including liver cancer (Huh7 cells) and brain cancer (MON, BT-12, BT-16, G401 cells) (140, 141); YLT-11, a novel Plk4 inhibitor, could suppress breast cancer cell proliferation (MDA-MB-231, MDA-MB-468, BT549, and MCF-7 cell lines) (142); and in human melanoma cell lines (A375 and Hs294T cells), cell proliferation was impaired after centrinone B treatment (11). The gene discussed is PLK4; the disease is breast cancer.