MMP9 and bladder transitional cell carcinoma: Endostatin, formed by gelatinase B/MMP-9 digestion of the type XVIII collagen α1 chain [72], blocks VEGFR2 and α5β1-mediated angiogenesis, inhibits gelatinase B/MMP-9 activity [286,287,288,289] and reduces metastasis in patients with high-grade transitional cell carcinoma of the bladder [290].