Gupta A, Gomes I, Bobeck EN, Fakira AK, Massaro NP, Sharma I, Cavé A, Hamm HE, Parello J, Devi LA. Collybolide is a novel biased agonist of κ-opioid receptors with potent antipruritic activity. Proc Natl Acad Sci U S A. 2016 May 24;113(21):6041–6. PMID: 27162327; PMCID: PMC4889365.