PTPN22 polymorphisms, but not R620W, were associated with the genetic susceptibility of systemic lupus erythematosus and rheumatoid arthritis in a Chinese Han population

Our data provide strong evidence that the rs1217414 and rs3811021 in PTPN22 gene might be common protective factors contributed to SLE and RA susceptibility in the Chinese Han population. While, the rs3765598 might increase the genetic susceptibility of SLE, but not RA.