MMP9 and breast cancer: In the scientific literature investigated, besides urinary metabolites related to many cancer forms, also specific biomarkers, such as sarcosine for prostate cancer [57,58,59,61,63,64,65], NGAL, MMP-9 and ADAM 12 for breast cancer [44,45], HCG for testicular cancer [133,134], h.KIM-1 for renal cancer [126] or Prostaglandin E2 for gastric cancer [82] have been reported.