TNF and rheumatoid arthritis: Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), interleukin-1 (IL-1), and IL-6, as well as macrophage colony-stimulating factor (M-CSF, also known as CSF-1) are involved in macrophage development, activation, growth, and differentiation, representing promising targets in RA [15].