Figure 1. Structural organization of IL-1 family member and their receptors.
A) Subfamilies of IL-1 ligands, grouped by structural similarity. The consensus sequence (AXD), located 9 amino-acids after the cleavage site is shown. B) IL-1 receptors and their cognate agonists and antagonists. The ILR subfamily is composed by receptors and accessory proteins (AcPs) for the cytokines of the IL-1 family. A novel nomenclature of ILRs has been recently proposed and it is as follows: IL-1R1 (IL-1RI), IL-1R2 (IL-1RII), IL-1R3 (IL-1RAcP), IL-1R4 (ST2), IL-1R5 (IL-18Rα), IL-1R6 (IL-1Rrp2, IL-36R), IL-1R7 (IL-18Rβ), IL-1R8 (also known as TIR8 or SIGIRR), IL-1R9 (TIGIRR- 2), IL-1R10 (TIGIRR-1).