CASP9 and breast cancer: To distinguish the efficiency of the synthetic nanoparticles (Epi-Nio and Epi-Nio-HA) for the inhibition of breast cancer, the expression of six different genes (i.e., CASP-3, CASP-9, and MMP-2, MMP-9, Cyc-D, and Cyc-E) involved in cell cycle, metastasis, and apoptotic pathways for 4T1 and SkBr3 breast cancer cell lines were assessed (Fig. 6A and B).