 Intracellular part of IL-17 receptors consists of several structural domains including SEFIR motif, a highly conserved motif within IL-17R family.Although SEFIR motif also serves as signaling molecule in IL-1R or Toll-like receptor families, its signaling features and associated adaptor molecules are quite different in IL-17 receptor family.In case of IL-17RA, it has longer cytoplasmic tail which contains some additional structural domains, such as TILL domain ("TIR-like loop") or inhibitory CBAD domain ("C/EBPβ-activation domain").