Following studies should compare the worsening effects of pro-inflammatory CD4+ T cell subpopulations or monocytes/macrophages on anti-inflammatory monocytes/macrophages or T cell subpopulations and the ameliorative effects of anti-inflammatory T cell subpopulations or monocytes/macrophages on pro-inflammatory monocytes/macrophages or CD4+ T cell subpopulations, which can determine which immune cells play a more important “commander” role in joint synovium of RA. Here, CD4 is linked to rheumatoid arthritis.