B-cell lymphoma 2 (Bcl-2) protein is an oncogene that normally acts as an apoptotic inhibitor and localizes to the mitochondrial membrane where it prevents the release of cytochrome c. The Bcl-2 protein family consists of over 20 proteins each containing at least one Bcl-2 homology (BH) domains and have either proapoptic or antiapoptotic activities.
