Unlike Urocortin I, and similar to Urocortin II, Urocortin III is highly selective for the CRF2 receptor and does not show affinity for the CRF binding protein.
Unlike Urocortin I, but similar to Urocortin II, Urocortin III has a strong affinity for the CRF2 receptor and lacks affinity for the CRF binding protein.