Bcl-2-Like Protein 1 (BCL2L1) is a member of the Bcl-2 family. BCL2L1 is expressed at high levels in cells that undergo a high rate of turnover, such as developing lymphocytes. BCL2L1 is a mitochondrial membrane protein. BCL2L1 contains four motifs, BH1, BH2 and BH4. The BH4 motif is required for anti-apoptotic activity. The BH1 and BH2 motifs are required for both heterodimerization with other Bcl-2 family members and for repression of cell death. BCL2L1 regulates cell death by blocking the voltage-dependent anion channnel (VDAC) and preventing the release of the caspase activator, CYC1, from the mitochondrial membrane. In addition, BCL2L1 promotes apoptosis.