IL-33 is a member of the IL-1 superfamily of cytokines, a determination based in part on the molecules β-trefoil structure, a conserved structure type described in other IL-1 cytokines, including IL-1α, IL-1β, IL-1Ra and IL-18.
IL-33 is a member of the IL-1 superfamily of cytokines, a determination based in part on the β-trefoil molecular structure, which is a conserved structural type found in other IL-1 cytokines such as IL-1α, IL-1β, IL-1Ra and IL-18.