Corticotropin-releasing hormone (CRH), also called CRF or corticoliberin, is a peptide hormone and neurotransmitter involved in the stress response. It belongs to corticotropin-releasing factor family. Marked reduction in this protein has been observed in association with Alzheimer disease and autosomal recessive hypothalamic corticotropin deficiency has multiple and potentially fatal metabolic consequences including hypoglycemia and hepatitis. In addition to production in the hypothalamus, this protein is also synthesized in peripheral tissues, such as T lymphocytes and is highly expressed in the placenta. In the placenta it is a marker that determines the length of gestation and the timing of parturition and delivery.