IL6 and Arthritis: Iguratimod is a new antirheumatic drug that suppresses the production of tumor necrosis factor α (TNFα), interleukin 6 (IL-6), and IL-8 in lipopolysaccharide-stimulated THP-1 cells [4], and inhibits cartilage and bone damage in DBA/1J mice with type II collagen (COL-II)-induced arthritis [5].