Common subunits of cytokine receptors and the functional redundancy of cytokines.

Several distinct cytokines often exhibit similar biological activities. The findings that high-affinity receptors for a group of cytokines with similar function share a common subunit with a critical role in signal transduction have provided a molecular basis for the functional redundancy of cytokines. Since the common subunit, together with distinct cytokine-specific receptor subunits, form high-affinity receptors, binding of one cytokine to its high-affinity receptor can be competed for by other cytokines in the same group.