The overall pooled sensitivity, specificity, PLR, NLR, and DOR of the IL-6 assay for PJI were 0.87 (95% CI, 0.82−0.90), 0.83 (95% CI, 0.79−0.87), 4.95 (95% CI, 3.19−7.68), 0.16 (95% CI, 0.07−0.38), and 36.27 (95% CI, 12.67−103.88), respectively, while those of serum CRP were 0.84 (95% CI, 0.79−0.88), 0.83 (95% CI, 0.79−0.87), 4.97 (95% CI, 3.03−8.17), 0.21 (95% CI, 0.12−0.36), and 27.24 (95% CI, 10.61−69.91), respectively (Fig. 3, 4, 5, 6, 7). This evidence concerns the gene IL6 and juvenile polyposis syndrome.