Background of the antigen
IL-1R9 is a member of the interleukin-1/Toll-like receptor family expressed in fetal brain. It is a single pass transmembrane protein with a highly conserved cytoplasmic region that is slightly longer than that of other family members. IL-1R9 is highly homologous to IL-1R8 and the IL-1 accessory protein receptor chains. The genes encoding IL-1R9 and IL-1R8 are both found on the X-chromosome in the region associated with X-linked non-syndromic mental retardation. Unlike other family members, IL-1R9 and IL-1R8 do not activate NF-kB.