IL-22 receptor is a heterodimeric complex of IL-22 receptor (IL-22R1) and a shared subunit, the IL-10 receptor (IL-10R2 or IL-10Rβ) of IL-10, IL-26 and IL-28/IL-19 [2].To elucidate the mechanism underlying augmented Th1 responses associated with administration of anti-IL-22 antibody we undertook studies to evaluate the expression of IL-22R1 and IL-10R2 during arthritis. The gene discussed is IL22; the disease is arthritic joint disease.