The IL-1 family member 7b translocates to the nucleus and down-regulates proinflammatory cytokines.

The IL-1 family member 7b (IL-1F7b) is a novel homolog of the IL-1 cytokine family discovered by computational cloning. We have reported that IL-1F7b shares critical amino acid residues with IL-18 and binds the IL-18-binding protein; in doing so, IL-1F7b augments the inhibition of IFN-gamma by the IL-18-binding protein. IL-1F7b also binds IL-18Ralpha but neither induces signal nor acts as a receptor antagonist.