Consistent with this notion, TNF is one of the main mediators of joint inflammation in inflammatory diseases such as rheumatoid arthritis (RA), which is associated with articular damage and systemic bone loss.12 13 Furthermore, in the clinical setting, treatment with TNF inhibitors has been shown to reduce articular erosion.14 However, the precise effects of TNF acting directly on human myeloid/MO/OC precursors remains ill-defined. The gene discussed is TNF; the disease is rheumatoid arthritis.