Introduction Click to copy section linkSection link copied! BCL2-related protein A1 (BFL1) is a member of the antiapoptotic B-cell lymphoma 2 (BCL2) protein family, the other members being BCL2, myeloid cell leukemia 1 (MCL1), B-cell lymphoma-extra-large (BCL-xl), B-cell lymphoma-w (BCL-w), and B-cell lymphoma 2 family protein resembling Boo (BCL-B).