CXCL13 and rheumatoid arthritis: The susceptible variants of RA were genotyped in 600 RA patients and 800 healthy controls, including rs148363003 of SLAMF6, rs117605225 of CXCL13, rs360136 of SWAP70, rs111597524 of NFKBIA, rs194757 of ZFP36L1 and rs1547233 of LINC00158. Synovial tissues were collected from the knee joint of 50 RA patients and 40 controls without osteoarthritis for the gene expression analysis.