OBSOLETE. The diazepam binding inhibitor is a 10kDa 86-residue polypeptide that acts as an endogenous ligand for a mitochondrial receptor (formerly regarded as a peripheral benzodiazepine binding site) in steroidogenic cells and regulates stimulation of steroidogenesis by tropic hormones. It also binds to the GABA-A receptor and modulates glucose-dependent insulin secretion and synthesis of acyl-CoA esters.