Cucurbitacin B changes nucleophosmin/B23 localization in human breast cancer cells. MCF-7 and MDA-MB-231 cells were stained with anti-nucleophosmin/B23 primary antibody. Alexa 568-conjugated anti-mouse IgG rabbit antibody was used as secondary antibody. DAPI was used for nuclear localization. Stained cells were analyzed by using confocal microscope. After exposure to 2.5 μM cucurbitacin B for 20 min. Translocation of nucleophosmin/B23 from nucleolus (red) to nucleoplasm (green) was observed.