Which of these is false regarding cytokines:

Cytokines mediate their effects by binding to specific high-affinity receptors on their target cells. Specific cytokines mediate specific reactions. Other important characteristics of cytokines Cytokines are soluble proteins produced by a wide variety of hematopoietic and non-hematopoietic cells. They are short acting. They are required for Regulation of growth Activation of the immune system Mediation of inflammatory response