MMP9 and breast cancer: However, our results are in keeping with others who have also reported high molecular weight (MW) proteins in urine of women at high risk for BC including matrix metallopeptidase-2, matrix metallopeptidase-9 (MMP9) and MMP9/neutrophil gelatinase-associated lipocalin complex (MW: 72 kDa, 92 kDa and 115 kDa respectively) [21].