Xu et al. (2022b) found that FIB was a significant biomarker and reported a sensitivity of 0.696 and higher specificity of 0.865; the AUC of FIB was only inferior to that of CRP among serum biomarkers. The present results indicate that FIB is a promising biomarker for identifying PJI: at a calculated cutoff of 3.95 g/L, the AUC, sensitivity, specificity, PPV, and NPV were 0.914, 0.864, 0.865, 0.784, and 0.915, respectively. The diagnostic value of FIB was not significantly different (P = 0.238) from that of CRP, according to the DeLong test comparing the respective AUCs. The gene discussed is CRP; the disease is juvenile polyposis syndrome.