Although IL-6 has been suggested to have relatively high diagnostic value in detecting PJI, and difference between serum and synovial fluid IL-6 tests in detecting PJI after hip, knee and shoulder replacements has also been initially evaluated, there was no systematic review and meta-analysis to evaluate the diagnostic accuracy of serum and synovial fluid IL-6 tests in detecting PJI among patients who underwent only hip and knee replacements. The gene discussed is IL6; the disease is juvenile polyposis syndrome.