Definition of "cytokine" [cytokine]

• Any of several regulatory proteins, such as the interleukins and lymphokines, that are released by cells of the immune system and act as intercellular mediators in the generation of an immune response. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Swine and avian flus kill healthy people by invoking an overly aggressive immune response called a cytokine storm."
• "Certain viral infections cause the body's immune system to lose control and attack itself, a phenomenon known as a cytokine storm."
• "Do patients have an unusually robust immune response to the virus -- the so-called cytokine storm?"