The anti-inflammatory cytokine IL-10 produced by T and B lymphocytes, activated monocytes, and macrophages has immunosuppressive properties in the control of periodontal bone loss.(8) A recent study in mice with arthritis has shown that high concentrations of HIF-1α are associated with increased IL-10 production by B cells, thus contributing to the reduction of the inflammatory response in the joints.(25) However, in the present study, a decrease in HIF-1α was found to be associated with an increased IL-10 synthesis. The gene discussed is HIF1A; the disease is Arthritis.