CASP9 and cancer: Apoptosis induction is validated as well through the decreased expression of cyclin D1, which is an essential regulator in cell cycle, its overexpression being linked to cancer development and progression [79]; collectively, experimental data indicate that Dy-doped Co ferrites act as efficient and selective anticancer agents in both types of cancer cells through mitochondrial apoptosis induction, as revealed by caspase-9, p53 and cyclin D1 regulated expressions.