Corticoliberin (CRH, aka corticotropin-releasing factor CRF) is a 41-amino acid amino peptide which, together with CRH-related peptides such as the urocortins (UCNs), play a role in coordinating endocrine, autonomic and behavioural responses to stress. These peptides exert their effects through binding and activation of two class B/Secretin family of GPCRs, CRHR1 and CRHR2 (aka CRFR1 and CRFR2 respectively). The corticotropin-releasing factor-binding protein (CRHBP) can bind to CRH with high affinity, inactivating it. CRHBP is expressed in the brains of all species examined to date but is uniquely expressed in human liver and placenta. In the brain, CRHBP is located in pituitary corticotropes, where it is under positive glucocorticoid control, and is likely to locally modulate CRH-induced ACTH secretion (Behan et al. 1993, Behan et al. 1995).