/ Thesaurus / C Synonyms of cytokine Find synonyms for: Noun1. cytokine, proteinusage: any of various protein molecules secreted by cells of the immune system that serve to regulate the immune systemWordNet 3.0 Copyright © 2006 by Princeton University. All rights reserved. Related Content Daily Word Quiz: quandary Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language