Can promote mitochondrial permeability transition and facilitate necrotic cell death under different types of stress conditions (By similarity). May have low affinity for heme (PubMed:15518569). Monomer. Interacts with LRPPRC. May interact with BCL2L1; an interaction with BCL2L1 was observed using a peptide, but not with the full-length protein. The full-length protein would have to undergo a major conformation change for the interaction to occur. Interacts with PDCD6. Mainly localized to the cytoplasm with a much lower abundance in the mitochondrion. Forms a distorted beta-barrel structure, with two helices that are packed against the outer surface of the barrel. Belongs to the HEBP family. Has been described as heme-binding protein (PubMed:15518569) in mouse, but the human protein does not bind hemin. His-42, a residue essential for heme binding in mouse, is not conserved in all orthologs, or in the heme-binding family member HEBP1.