BCL2L15 is a 163 amino acid protein and novel member of the Bcl-2 family that contains both BH2 and BH3 regions, but not BH1, BH4 or a C-terminal hydrophobic membrane anchor. Like Bcl-GL, Bfk does not bind to any Bcl-2 family members, even though its BH3 motif can mediate association with prosurvival proteins. Bfk localizes to cytoplasm, but unlike Bcl-GL, Bfk does not associate with organelles. Existing as four alternatively spliced isoforms, the pro-apoptotic isoforms of Bfk may help to pro