showed that CRP is not a normal constituent of urine and is not a biomarker of local inflammation in the urinary tract (27); similarly, in two studies that measured uCRP in patients with lower urinary tract symptoms (LUTS) and children with urinary tract infections (UTI), uCRP was not found to be a specific biomarker for either condition (27, 28). Here, ISG15 is linked to bacterial urinary tract infection.