Interleukin (IL)-23, a heterodimeric protein composed of p40 and p19 subunits, mediates chronic joint inflammation by maintaining the survival of T helper 17 (Th17) cells in concert with induction of tumor necrosis factor (TNF), IL-1β, and IL-6 in RA FLSs [3]. The gene discussed is TNF; the disease is rheumatoid arthritis.