In the autoimmune setting, anti-human GM-CSF mAb (63, 64) and anti-human GM-CSF receptor α mAb (65, 66) have also been shown to ameliorate rheumatoid arthritis in clinical trials, reinforcing the work of several decades that GM-CSF is a key proinflammatory cytokine. The gene discussed is CSF2; the disease is rheumatoid arthritis.