CSF2 and rheumatoid arthritis: GM-CSF has been shown to activate monocytes and macrophages in inflamed tissues, as in rheumatoid arthritis, and activated macrophages affect the release of chemokines, such as IL-1β and MIP-1α.8 It has been shown that MIP-1α and IL-1β have important pathological functions in the development of various inflammatory and autoimmune diseases and are at high levels in the regions in which periodontitis is active.36,37 Therefore, the current findings of IL-1β and MIP-1α are unsurprising.