IL‐17A and its receptor are the founding members of a recently described cytokine family,
with unique sequences and functions in the immune system and elsewhere. Consisting of
six ligands (IL‐17A–F) and five receptors (IL‐17RA–IL‐17RE) in mammals, these molecules
have distinct primary amino acid structures with only minimal homology to other cytokine
families. By far the best studied of these cytokines to date are IL‐17A and its receptor, IL‐
17RA. IL‐17A is produced primarily by T cells, and is the hallmark cytokine of a newly …