TNF and rheumatoid arthritis: Recently, it has been observed that treating rheumatoid arthritis in mice with TP nano-composite hydrogel can reduce leukocyte infiltration, alleviate cartilage destruction, and decrease the concentrations of the inflammatory cytokines interleukin (IL)-1β, tumor necrosis factor-α (TNF-α), and IL-6, thereby effectively improving joint inflammation [1].