CASP9 and breast cancer: Also, Western blot analysis clearly showed that the protein levels of Caspase-9, PARP and Caspase-8 were downregulated, while CL-caspase-9, CL- PARP and CL-caspase-8 were upregulated after EM-2 treatment, which further confirmed the occurrence of cell apoptosis induced by EM-2 in both LC and BC cells (Figure 4C).