Bcl2 is a member of the B cell lymphoma 2 protein family. Members of this family regulate cell death in multiple cell types and can have either proapoptotic or antiapoptotic activities. The protein encoded by this gene inhibits mitochondrial-mediated apoptosis. This protein is an integral outer mitochondrial membrane protein that functions as part of signaling pathway that controls mitochondrial permeability in response to apoptotic stimuli. This protein may also play a role in neuron cell survival and autophagy. Abnormal expression and chromosomal translocations of this gene are associated with cancer progression in numerous tissues.