CXCR4 and rheumatoid arthritis: This directly proportional relation of ITIH4 and CXCR4 expression in knockdown assay signifies that ITIH4 increased expression triggers CXCR4 activation, suggesting that ITIH4 might act as a ligand for CXCR4 receptor regulating chemokine mediated signaling pathways in RA-FLS.