Table 1 The receptors, receptor–accessory proteins, and endogenous inhibitors of the IL-1 family of cytokines.

IL-1 family members (in bold) are grouped into four subfamilies. The receptors and receptor–accessory proteins that transduce signals from each family member are listed, as well as inhibitors of signaling. The nomenclature used here follows that of the HUGO Gene Nomenclature Committee for ILs (www.genenames.org/cgi-bin/genefamilies/set/601) and IL receptors (www.genenames.org/cgi-bin/genefamilies/set/602).

Agonist
subfamily
CytokineReceptorReceptor–
accessory
protein
Endogenous
inhibitors
IL-1IL-1α
IL-1β
IL-1R1IL-1RAPIL-1R2
IL-1Ra
SIGIRR
sIL-1RAP
sIL-1RAP-β
IL-18IL-18IL-18R1IL-18RAPIL-18BP
IL-37
SIGIRR
IL-33IL-33IL-1RL1IL-1RAPSIGIRR
sIL-1RL1
sIL-1RAP
sIL-1RAP-β
IL-36IL-36α
IL-36β
IL-36γ
IL-1RL2IL-1RAPIL-36Ra
IL-1F10
sIL-1RAP
sIL-1RAP-β