MMP9 and bacterial urinary tract infection: In an unpublished pilot study (n = 100), we evaluated five candidate urine markers [neutrophil gelatinase-associated lipocalin (NGAL), interleukins 8, 6, and 1β (IL-8, IL-6, and IL1-β), and matrix metalloproteinase 9 (MMP-9)] selected based on literature [17–28], and found that three showed a promising correlation with uropathogen detection by M-PCR and SUC in patients symptomatic for UTI: NGAL and IL-8 had good sensitivity and specificity while IL-1β had very high sensitivity (Supplemental Table S2).