Effects of Ezetimibe on the viability, proliferation, and cell cycle of TNBC cells. (A) Viability of MDA-MB-231 and 4T1 cells treated with different concentrations of Ezetimibe (0, 1, 5, 10, 15, 20, 40, 60, 80, 100 μmol/L) for 48 h was detected using the CCK-8 assay. (B) Cell cloning experiments were performed to measure the colony formation of MDA-MB-231 cells after 10 days and 4T1 cells after 14 days of treatment with different concentrations of Ezetimibe (0, 20, 40 μmol/L). (C) Flow cytometry analysis was conducted to examine cell cycle distribution of MDA-MB-231 and 4T1 cells treated with different concentrations of Ezetimibe (0, 20, 40 μmol/L) for 48 h. (D) Western blotting was performed to determine the expression levels of Ki67, CDK2, CDK4, and CyclinD1 proteins in MDA-MB-231 and 4T1 cells treated with different concentrations of Ezetimibe (0, 20, 40 μmol/L) for 48 h. Representative results from three independent experiments are shown, and the data are presented as mean ± standard deviation (Mean ± SD): *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001. Here 0 μmol/L Ezetimibe refers to 0.1 % (v/v) DMSO solution.