However, while Il6 (interleukin-6) was unaltered, a reduced expression of Il1b (interleukin-1beta), a master pro-inflammatory cytokine in joint inflammation, was significantly reduced in the OA knees of Cxcl9-deficient mice 4 weeks after ACLT (Fig. 7E). The gene discussed is CXCL9; the disease is inflammatory response.