The synovial fluid of patients with very early RA is characterized by elevated levels of cytokines that are survival factors for T cells (IL-2, IL-4 and IL-15) and neutrophils (granulocyte-macrophage colony-stimulating factor [GM-CSF] and granulocyte colony-stimulating factor [G-CSF]). The gene discussed is CSF3; the disease is rheumatoid arthritis.