Soricidin
Soricidin is a paralytic oligopeptide found in the venomous saliva of the northern short-tailed shrew (Blarina brevicauda);[https://www.uniprot.org/uniprot/P0C2P6 Soricidin - Blarina brevicauda (Northern short-tailed shrew)] at UniProt; version 15; published October 31, 2012; retrieved December 13, 2013 in the wild, shrews use it to paralyze their prey (typically insects).[https://www.jstor.org/stable/1380494 Venom of the Short-Tailed Shrew (Blarina brevicauda) as an Insect Immobilizing Agent], by Irwin G. Martin, in the Journal of Mammalogy (archived at JSTOR); Vol. 62, No. 1 (Feb., 1981), pp. 189-192 Its name is a reference to "Soricidae", the family to which shrews belong.[http://pubs.acs.org/cen/critter/8242shrews.html The Stunning Saliva Of Shrews: Researchers are trying to unravel the mystery of the shrew's venomous brew], by Rachel Sheremeta Pepling; in Chemical & Engineering News; published October 13, 2004; retrieved December 13, 2013
In addition to blocking transmission of nerve impulses[http://www.cbc.ca/news/technology/shrew-spit-tames-cancer-cells-1.908339 Shrew spit tames cancer cells] at CBC.ca; published May 24, 2010; retrieved December 13, 2013 by inhibiting sodium channels, soricidin also inhibits the TRPV6 calcium channel,[http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0058866 In Vivo Detection of Human TRPV6-Rich Tumors with Anti-Cancer Peptides Derived from Soricidin], by Chris V. Bowen, Drew DeBay, H. Stephen Ewart, Pamela Gallant, Sean Gormley, T. Toney Ilenchuk, Umar Iqbal, Tyler Lutes, Marzia Martina, Geoffrey Mealing, Nadine Merkley, Sandra Sperker, Maria J. Moreno, Christopher Rice, Raymond T. Syvitski, and John M. Stewart; in PLoS One; published: March 15, 2013; retrieved December 13, 2013; DOI: 10.1371/journal.pone.0058866 which is over-expressed in many epithelial-cell cancers; as a result, soricidin is able to selectively induce apoptosis[http://online.liebertpub.com/doi/pdf/10.1089/adt.2009.0241 The Seventh Annual Ion Channel Retreat - Vancouver, Canada, June 29 – July 1, 2009 - MEETING REPORT], by Saranna Brugger, Susannah Kennedy, and Noel King; in ASSAY and Drug Development Technologies; vol. 8, no. 1, February 2010; doi: 0.1089/adt.2009.0241 in breast, ovarian, and prostate cancer.[https://www.theglobeandmail.com/life/health-and-fitness/health/quest-for-a-wonder-drug-started-with-shrew-bait/article4470731/ Quest for a wonder drug started with shrew bait], by Dakshana Bascaramurty; at The Globe and Mail; published August 8, 2012; retrieved December 13, 2013
It is 54 amino acids long. It was first extracted and identified in 2000, as a result of basic research by Jack Stewart of Mount Allison University.[http://www.macleans.ca/2010/07/01/open-up-and-say-aah/ Open up and say 'aah'], by Tom Henheffer; at Maclean's; published July 1, 2010; retrieved December 13, 2013