To determine whether amelioration of arthritis in mice with CIA in which IL-23 was silenced was associated with interference of IL-23 downstream signaling and miR-223 levels, the expression of phosphorylated signal transducers and activators of transcription 4 (p-STAT4) and miR-223 were analyzed by immunohistochemistry and in situ hybridization. The gene discussed is STAT4; the disease is arthritic joint disease.