Figure 3. A novel mechanism generating cytokine diversity.
A cytokine acts on the cells (target 1) that express a specific
receptor. With certain cytokines, such as IL-6 and CNTF, the complex
composed of the cytokine and its soluble form of receptor subunit
also acts on the cells (target 2) that express only a subset of the
receptor subunits, on which the original cytokine cannot act. IL-12,
identified as a cytokine, is a complex composed of a cytokine and the
soluble form of a cytokine receptor.
