cytokine cy·to·kine (sī'tə-kīn')
Any of several nonantibody proteins, such as lymphokines, that are released by a cell population on contact with a specific antigen and act as intercellular mediators, as in the generation of an immune response.
any of a group of small, short-lived proteins that are released by one cell to regulate the function of another cell, thereby serving as intercellular chemical messengers. Cytokines effect changes in cellular behaviour that are important in a number of physiological processes, including reproduction, growth and development, and injury repair. However, they are probably best known for the roles they play in the immune system's defense against disease-causing organisms
Learn more about cytokine with a free trial on Britannica.com.