Cytochrome Cis an electron carrier protein that localizes in mitochondrion intermembrane space and has been identified as one of the key signaling molecules of apoptosis or programmed cell death. Suppression of the anti-apoptotic members or activation of the pro-apoptotic members of the Bcl2 family leads to altered mitochondrial membrane permeability resulting in release of cytochrome c into the cytosol.
