IL-21 induces the expression of Beclin-1, autophagy-related 5 (Atg5), and LC3-phosphatidylethanolamine conjugate 3-II (LC3-II) through the inhibition of C/EBP homologous protein (CHOP) in FLS from rats with adjuvant-induced arthritis. The gene discussed is ATG5; the disease is arthritic joint disease.