CD4 and rheumatoid arthritis: The CXC chemokine also have a role in RA due to their chemotactic effects on cell populations such as neutrophils (CXCL1, CXCL5, CXCL8), monocytes, and T cells (CXCL4, CXCL9, CXCL10, CXCL12, CXCL16), which correlates with the presence of CXCR3+ T cells, recruitment of CXCR6+ Th1 effector cells, and accumulation of CD4+ T cells in the RA synovium (143).