Meanwhile, it has been proposed that some cytokines secreted by the macrophages and chondrocytes, including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and matrix metalloproteinase (MMPs), are closely related to RA [7,8]. Here, TNF is linked to rheumatoid arthritis.