The effects of several individual and combined treatments on γH2AX foci formation in MDA-MB-231 cells. MDA-MB-231 cells were treated for 3 days with vehicle (control), 1 μM 4OHT, 10 μM TMCG and 5 μM DIPY (TMCG/DIPY) or with the triple combination TMCG/DIPY/4OHT at the specified concentrations. MDA-MB-231 cells were examined by immunofluorescence for γH2AX foci (red) and DAPI (blue). The histograms represent the positive γH2AX foci cells and the number of γH2AX foci per nucleus in γH2AX focus-positive cells. In both cases, *indicates that P < 0.05 when compared to untreated cells subjected to 4OHT treatment and **indicates that P < 0.05 when compared to untreated cells subjected to 4OHT and TMCG/DIPY treatment.