The present invention provides .beta.-subunit-Associated Regulator of Apoptosis, or BARA, polypeptides and nucleic acid molecules encoding the same. The invention also provides selective binding agents, vectors, host cells, non-human transgenic animals, devices and methods for producing BARA polypeptides. The invention further provides compositions comprising BARA nucleic acids, polypeptides, and fusions or derivatives thereof. The invention further provides methods for treating, preventing, or ameliorating a medical disease, condition, or disorder comprising administering BARA or BARA compositions, as well as methods of diagnosing a pathological condition related to BARA. Still further, the invention provides methods of modulating levels of BARA expression and methods of determining whether a compound stimulates or inhibits BARA polypeptide activity or BARA polypeptide production.